0382:

#include<iostream>
using namespace std;
main(){
  int n, k;
  cin >> n >> k;
  int sum = 0;
  for ( int i = 0; i < k; i++ ){
    int x; cin >> x;
    sum += x;
  }
  n++;
  cout << sum/n + (sum%n==0?0:1) << endl;
}