#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;
        }