#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	ll n, x, sum = 0;
	cin >> n >> x;
	for (ll i = 0; i < n; i++)
	{
		ll p;
		cin >> p;
		sum += p;
	}
	cout << (x >= sum ? 0 : sum - x);
}