/*

Vassilis Athitsos
UTA ID: 

*/

#include <stdio.h>



int main( void )
{
	int number;
	int sum;
	int i;

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

	sum = 0;
	i = 0;

	while(i <= number)
	{
		sum = sum + i;
		i++;
	}

	printf("sum of numbers from 0 to %d is %d\n", number, sum);
}