For a better world

#include <stdio.h>

int main(void)

{
	int n = 0;
	int sum = 0;
	
	scanf("%d", &n);
	
	if (n>=1 and n<=10000)
	{
		for (int i=1; i<=n; i++)
		{
			sum = sum + i;
		}
		printf("%d", sum);
	}
	
	return 0;
}