/*
 * Program to compute sum of integers entered as input,using recursion.
 *
 * Input is any number of integers, ending with anything but an integer.
 */
#include <stdio.h>

int sum(void);

int main(void) {
	printf("enter integers, anything else to stop\n");
	printf("sum is %d\n", sum());

	return 0;
}
 
/*
 * compute and return sum of integers from stdin, stopping when anything else
 * is entered
 */
int sum(void) {
	int input;
	if (scanf("%d", &input) != 1) {
                /* non-integer input -- the end */
		return 0;
	}
	else {
		/* add this input to sum of remaining inputs */
		return input + sum();
	}
}