#include<iostream>
#include<iomanip>
using namespace std;
int main()
{
    int num;
    cin>>num;
    try
    {
        if(n<=0 && num>12)
        {
            throw "Invalid input";
        }
    int deposit;
    int total = 0;
     for(int i=0; i<num;i++)
     {
         cin>>deposit;
         if(deposit<0)
         {
             throw "Invalid input";
         }
         total += deposit;
         }
         cout<<total;
    }
    catch(const char* msg)
    {
        cout<<msg;
    }
    return 0;
}