View Code of Problem 30

import java.util.Scanner;
 
  public class Main{
    public static void main(String[] args){
    	Scanner scan=new Scanner(System.in);
      while(scan.hasNext()){
      	int a=scan.nextInt();
        int sum=0;
        int i;
        for(i=0;i<=a;i++){
        	sum=sum+i;
        }
        
      	
      	System.out.println(sum);
        
    }
    }
  	
  }