#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 "Invalid input";
            }
            total +=deposit;
        }
        cout<<total;
    }
    catch(const char*msg){
        cout<<,msg;
}
return 0;