#include <bits/stdc++.h>
using namespace std;

using ll = long long;

int main(){
  ll n, x; cin >> n >> x;
  vector<ll> a(n);
  ll s = 0;
  for(ll i=0; i<n; i++) cin >> a[i];
  for(ll i=0; i<n; i++) s += a[i];

  ll z = 0;
  cout << max(s - x, z) << endl;
}