feat: Add FunctionsCC3 class with calculateSum using user input

WHAT the code does:
- Defines a `FunctionsCC3` class with a static method `calculateSum(int num1, int num2)` that returns the sum of two numbers.
- Uses `Scanner` to read two integers from the user.
- Calls `calculateSum()` with the input values and prints the result in a formatted message.

WHY this matters:
- Demonstrates combining **user input handling** with method calls.
- Shows how to pass values dynamically to methods instead of hardcoding.
- Reinforces the distinction between returning results vs printing inside the method.

HOW it works:
1. Program prompts for `"Enter first number:"` and `"Enter second number:"`.
2. Reads values `a` and `b` via `Scanner`.
3. Passes them into `calculateSum(a, b)` → computes and returns sum.
4. Prints result in format: `"Sum = X"`.

Tips & gotchas:
- `Scanner` should be closed after use (`sc.close()`).
- Input validation (e.g., handling non-integer input) is not included.
- Works only for integers — could be extended to handle doubles.
- For larger numbers, `long` may be safer to prevent overflow.

Use-cases:
- Educational example for **method with return value + user input**.
- Foundation for calculator-style programs.
- Can be extended with additional operations (subtract, multiply, divide).
- Useful for practicing console-based interactive applications.

Short key: class-functions cc3-calculate sum-user input.

Signed-off-by: https://github.com/Someshdiwan <[email protected]>

Author: Someshdiwan

Section10Methods/PracticeProblems/src/FunctionsCC3.java

@@ -1,11 +1,18 @@
-//Print the returned value directly.
+import java.util.Scanner;
 
 public class FunctionsCC3 {
-    public static int calculateSum(int num1, int num2)
-    {
+    public static int calculateSum(int num1, int num2) {
         return num1 + num2;
     }
+
     public static void main(String[] args) {
-        System.out.println(calculateSum(3, 4));
+        Scanner sc = new Scanner(System.in);
+        System.out.print("Enter first number: ");
+        int a = sc.nextInt();
+
+        System.out.print("Enter second number: ");
+        int b = sc.nextInt();
+
+        System.out.println("Sum = " + calculateSum(a, b));
     }
-}
+}