#include <stdio.h>

int sum_up_to_number(int number)
{
	int i;
	int sum = 0;

	for (i = 0; i <= number; i++)
	{
		sum = sum + i;
	}

	return sum;
}


int main()
{
	int input;
	int result;

	printf("enter a number:\n");
	scanf("%d", &input);

	result = sum_up_to_number(input);
	printf("result = %d\n", result);
}