#include<iostream>
using namespace std;
int main(){
    int n;
    cin >> n;
    try{
        if(n <= 0|| n>12){
            throw "invalid input";
        }
        int deposit;
        int total = 0;
        for (int i=0; i<n;i++){
            cin >>deposit;
        }
        if (deposit <0){
            throw"ivalid input";
        }
        total + deposit;
    }
    cout << total;
}
catch (const char* msg){
    cout << msg;
}
return 0;
}