diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..38a2608
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+/.idea/
+/Lesson_1/Lesson_1.iml
+/out/
diff --git a/Lesson_1/src/Calculator.java b/Lesson_1/src/Calculator.java
new file mode 100644
index 0000000..9871a35
--- /dev/null
+++ b/Lesson_1/src/Calculator.java
@@ -0,0 +1,56 @@
+import java.util.Scanner;
+
+public class Calculator {
+    public static void main(String[] args) {
+        Scanner sa = readInput("Enter first number: ");
+        int a = sa.nextInt();
+        Scanner sb = readInput("Enter second number: ");
+        int b = sb.nextInt();
+        Scanner sop = readInput("Enter operation type (+, -, *, /, ^, %): ");
+        String op = sop.next();
+        System.out.println("Result is: " + getResult(a, b, op));
+    }
+
+    private static Scanner readInput(String prompt) {
+        System.out.println(prompt);
+        return new Scanner(System.in);
+    }
+
+    private static Boolean isOpValid(String op) {
+        String[] opTypes = {"+", "-", "*", "/", "^", "%"};
+
+        for (String opType: opTypes) {
+            if (opType.equals(op)) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    private static int getResult(int a, int b, String op) {
+        if (isOpValid(op)) {
+            if (op.equals("+")) {
+                return a + b;
+            } else if (op.equals("-")) {
+                return a - b;
+            } else if (op.equals("*")) {
+                return a * b;
+            } else if (op.equals("/")) {
+                return a / b;
+            } else if (op.equals("^")) {
+                return customPow(a, b);
+            } else {
+                return a % b;
+            }
+        }
+        return 0;
+    }
+
+    private static int customPow(int a, int b) {
+        int result = 1;
+        for (int i = 0; i < b; i++) {
+            result *= a;
+        }
+        return result;
+    }
+}
diff --git a/Lesson_1/src/ConditionalStatement.java b/Lesson_1/src/ConditionalStatement.java
new file mode 100644
index 0000000..b176a6f
--- /dev/null
+++ b/Lesson_1/src/ConditionalStatement.java
@@ -0,0 +1,35 @@
+public class ConditionalStatement {
+    static int age = 16;
+    static boolean isMale = true;
+    static float height = 1.81F;
+    static String name = "Michael";
+
+    public static void main(String[] args) {
+        if (age > 20) {
+            System.out.println("age > 20");
+        }
+
+        if (isMale) {
+            System.out.println("isMale");
+        }
+
+        if (!isMale) {
+            System.out.println("!isMale");
+        }
+
+        if (height < 1.80F) {
+            System.out.println("height < 1.80F");
+        } else {
+            System.out.println("height >= 1.80F");
+        }
+
+        if (name.startsWith("M")) {
+            System.out.println("name.startsWith(\"M\")");
+        } else if (name.startsWith("И")) {
+            System.out.println("name.startsWith(\"И\")");
+        } else {
+            System.out.println("name.startsWith(\"smth else\")");
+        }
+
+    }
+}
diff --git a/Lesson_1/src/Cycle.java b/Lesson_1/src/Cycle.java
new file mode 100644
index 0000000..ce39267
--- /dev/null
+++ b/Lesson_1/src/Cycle.java
@@ -0,0 +1,23 @@
+public class Cycle {
+    public static void main(String[] args) {
+        for (int i = 0; i <= 20; i++) {
+            System.out.println(i);
+        }
+
+        int i = 6;
+        while (i > -7) {
+            System.out.println(i);
+            i -= 2;
+        }
+
+        i = 10;
+        int result = 0;
+        do {
+            if (i % 2 != 0) {
+                result += i;
+            }
+            i++;
+        } while (i < 20);
+        System.out.println(result);
+    }
+}
diff --git a/Lesson_1/src/MyFirstApp.java b/Lesson_1/src/MyFirstApp.java
new file mode 100644
index 0000000..e93101c
--- /dev/null
+++ b/Lesson_1/src/MyFirstApp.java
@@ -0,0 +1,5 @@
+public class MyFirstApp {
+    public static void main(String[] args) {
+        System.out.println("Hello, world");
+    }
+}
diff --git a/Lesson_1/src/MyFirstGame.java b/Lesson_1/src/MyFirstGame.java
new file mode 100644
index 0000000..9f8abee
--- /dev/null
+++ b/Lesson_1/src/MyFirstGame.java
@@ -0,0 +1,40 @@
+import java.time.LocalDateTime;
+import java.util.InputMismatchException;
+import java.util.Scanner;
+
+public class MyFirstGame {
+    public static void main(String[] args) {
+        byte guess = random();
+//        byte guess = 12;
+        Scanner input;
+        System.out.println("I guess a random number from 0 to 100. What's it? ");
+        byte userInput = 0;
+        int triesNumber = 0;
+        do {
+            triesNumber++;
+            input = new Scanner(System.in);
+            try {
+                userInput = input.nextByte();
+                if (guess < userInput) {
+                    System.out.println("Wrong number! Your value is greater than my. Try again: ");
+                } else if (guess > userInput) {
+                    System.out.println("Wrong number! Your value is less than my. Try again: ");
+                }
+            } catch (InputMismatchException ex) {
+                System.out.println("Please use only numbers (from 0 to 100)");
+            }
+
+        } while (guess != userInput);
+        System.out.println("Good job, you found it! With " + triesNumber + " tries");
+    }
+
+    private static byte random() {
+        LocalDateTime now = LocalDateTime.now();
+        int seconds = now.getSecond();
+        if (seconds % 2 == 0) {
+            return (byte) (now.getNano() / 10000000);
+        } else {
+            return (byte) (now.getNano() / 10000000 + 1);
+        }
+    }
+}
diff --git a/Lesson_1/src/Unicode.java b/Lesson_1/src/Unicode.java
new file mode 100644
index 0000000..744d198
--- /dev/null
+++ b/Lesson_1/src/Unicode.java
@@ -0,0 +1,8 @@
+public class Unicode {
+    public static void main(String[] args) {
+        for (int i = 9398; i < 10178; i++) {
+//            System.out.println(Character.toString((char)i));
+            System.out.println((char)i);
+        }
+    }
+}
diff --git a/Lesson_1/src/Variable.java b/Lesson_1/src/Variable.java
new file mode 100644
index 0000000..51f6bd8
--- /dev/null
+++ b/Lesson_1/src/Variable.java
@@ -0,0 +1,22 @@
+public class Variable {
+    public static void main(String[] args) {
+        byte cpuCores = 4;
+        short numOfPackages = 3600;
+        int gpuMemSizeInKB = 8 * 1024 * 1024;
+        long totalDiskSpaceInKB = 256 * 1024 * 1024;
+        float cpuFrequencyGHz = 3.60f;
+        double memorySizeGB = 6.1;
+//        char[] osType = "Ubuntu".toCharArray();
+        char[] osType = {85, 98, 117, 110, 116, 117} /* "Ubuntu".toCharArray() the same */;
+        boolean isUpToDate = true;
+
+        System.out.println("CPU cores count: " + cpuCores);
+        System.out.println("Number of packages: " + numOfPackages);
+        System.out.println("GPU memory size in KBs: " + gpuMemSizeInKB);
+        System.out.println("Total disk space in KBs: " + totalDiskSpaceInKB);
+        System.out.println("CPU frequency in GHz: " + cpuFrequencyGHz);
+        System.out.println("Memory size in GBs: " + memorySizeGB);
+        System.out.println("OS type: " + new String(osType));
+        System.out.println("Is up-to-date: " + isUpToDate);
+    }
+}