View Code of Problem 30

#include <stdio.h>
#include <math.h>
int main()
{
	int n, sum = 0;
	while(scanf("%d", &n) != EOF)
	{
		for(int i = 1; i <= n; i++)
		{
			sum += i;
		}
		printf("%d\n", sum);
	}
	return 0;
}