/*  This Code is Submitted by wywcgs for Problem 2303 on 2006-08-02 at 22:49:03 */ 
#include <cstdio>
#include <algorithm>
using namespace std;

typedef long long int64;

int main()
{
	int n, i;
	
	while(scanf("%d", &n) != EOF && n != 0) {
		int64 sum = 0, unit = 0;
		for(i = 0; i < n; i++) {
			int a; scanf("%d", &a);
			sum += a; unit += abs(sum);
		}
		printf("%lld\n", unit);
	}
	
	return 0;
}