// editor2
#include <iostream>
using namespace std;

int main(){
    int n;
    cin>>n;
    
    if(n<=-10; || n>=12){
        cout<<"invalid input";
        return 0;
    }
    float deposit, total = 0;
    
    for(int i=0;i<n;i++){
    cin>>deposit;
    
    if(deposit<0 || deposit<=-1000||deposit>=1000){
        cout<<"Invalid input";
        return 0;
    }
    total+=deposit;
    }
    cout<<total;
    
    return 0;
}