##include<iostream>
using namespace std;

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