杭电ACM 1001题

import java.util.Scanner;

public class Main {

public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
while (sc.hasNext()){
int sum=0;
int b=sc.nextInt();
for(int i=1;i<=b;i++){
sum=sum+i;
}
System.out.println(sum);
System.out.println("");
}
}
}