SumOfEvenNums.java

import java.util.Scanner;

public class SumOfEvenNum {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        while (true) {
            System.out.print("Enter a number: ");
            int n = sc.nextInt();
            int sum = 0;
            for (int i = 2; i <= n; i += 2) {
                sum += i;
            }
            System.out.println("The sum of even numbers from 1 to " + n + " is: " + sum);
        }
    }
}