// summing.c -- sums integers entered interactively
#include <stdio.h>

const char* PROMPT = "Please enter an integer to be summed "
"(or q to quit): ";

int main(void)
{
	long num;
	// initialize sum to zero
	long sum = 0L;
	int status;

	printf(PROMPT);
	status = scanf("%ld", &num);
	// == means "is equal to"
	while (status == 1)
	{
		sum = sum + num;
		printf(PROMPT);
		status = scanf("%ld", &num);
	}
	printf("Those integers sum up to %ld.\n", sum);
	return 0;
}