[热身题][hdoj_1001]Sum Problem

// hdoj_1001 Sum Problem

#include <stdio.h>
int main()
{
	int n, i, sum;
	while(scanf("%d", &n) != EOF)
	{
		sum = 0;
		for(i = 0; i <= n; i ++)
			sum = sum + i;
		printf("%d\n\n", sum);
	}
	return 0;
}