#include <iostream>
using namespace std;
int n, a, s;
int main()
{
	while(1)
	{
		cin >> n;
		if(!n)
			return 0;
		s = 0;
		while(n --)
		{
			cin >> a;
			s += a;
		}
		cout << s << endl;
	}
	return 0;
}