#include<iostream>
using namespace std;
int main(){
    int n;
    cin>>n;
    if(n<0){
        cout<<"Invalid input";
    }
    int deposite;
    int totalsavings=0;
    for(int i=0;i<n;i++){
        cin>>deposite;
        if(deposite<0){
            cout<<"Invalid input";
            return 0;
        }
        totalsavings +=deposite;
    }
    cout<<totalsavings
  
    return 0;
    
}