java program

import java.util.*;

class sum {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("10");
int n = sc.nextInt();
int i,sum=0;

for(i=0;i<=n;i++)
{
sum = sum + i;
}

System.out.println("Sum of first "+n+" natural nos = "+sum);
}
}