View Code of Problem 30

#include <iostream>
#include<string.h>
#include<math.h>
using namespace std;
int main()
{
	int n;
	
	while(scanf("%d",&n)!=EOF)
	{
		int sum=0;
		for(int i=1;i<=n;i++)
		sum+=i;
	cout<<sum<<endl;
	}
	return 0;
 }