#include<iostream>
#include<algorithm>
using namespace std ;
int main()
{
  int n;
  cin>>n;
  int minn = 0 ; 
  int arr[n];
  for(int i = 0 ; i<n ; i++)
 {
     cin>>arr[i];
 minn = min(minn,arr[i]);
 
 }
 cout<<abs(minn);
}