import java.util.*;
class Main{
public static void main(String args[]){
Scanner sc=new Scanner(System.in);
while(sc.hasNextInt()){
int n = sc.nextInt();
if(n==0){
break;
}
int t, s= 0;
while(n-->0){
t = sc.nextInt();
s = s+t;
}
System.out.println(s);
}
}