4 1 2 3 4
5 1 2 3 4 5
0 

10
15

#include<iostream>
#include<cstdio>
using namespace std;
int main()
{
    int n,a,sum;
    while(scanf("%d",&n)!=EOF)
    {
        if(n==0)
            break;
        sum=0;
        for(int i=0;i<n;i++)
        {
            scanf("%d",&a);
            sum+=a;
        }
        printf("%d\n",sum);
    }
    return 0;
}