#include<iostream>
#include<algorithm>
using namespace std;
int n,m,a[1114514];
bool check(int h)
{
	int sum = 0;
	for(int i = 1;i <= n;i++)
		if(a[i] > h)
			sum += (a[i]-h);
	return sum >= m;
}
int main()
{
	cin >> n >> m;
	for(int i = 1;i <= n;i++) cin >> a[i];
	int l = 0,r = 1000000000;
	while(l < r)
	{
		int mid = (l + r + 1) >> 1;
		if(check(mid)) l = mid;
		else r = mid - 1;
	}
	cout << l;
	return 0;
}