Untitled

#include <iostream>
#include <cmath>
using namespace std;

int main() {

	int a,past,count = 0;
	bool running = true;

	cin >> a;
	past = -3572349;
	
	while(running) {
		if (past == 0 && a == 0) {
			break;
		}
		else{
			count += a;
			past = a;
		}
		cin >> a;
	}
	cout << count;
}