/*没小鸟的钟鼎皓盗我号骗分*/
/*小心slz钟鼎皓 药哥嗑药抄题解不改头文件！！！！！！！！！！！！！！！！！！！！！！！！！！*/
#include <bits/stdc++.h>
#define LL long long
using namespace std;
const int N = 1e6 + 10;
const int INF = 0x3f3f3f3f;
int n , m , l , r , ans;
int a [N];
bool check (int mid)
{
	int sum = 0;
	for (int i = 1; i <= n; i++)
	{
		if (a [i] > mid)
		{
			sum += a [i] - mid;
		}
	}
	return (sum >= m);
}
int main()
{
	    cin >> n >> m;
		for (int i = 1; i <= n; i++)
	    {
	    	cin >> a [i];
		}
		sort (a + 1 , a + 1 + n); 
		l = 1;
		r = a [n];
		while (l <= r)
		{
			int mid = (l + r) >> 1;
			if (check (mid))
			{
				ans = mid;
				l = mid + 1;
			}
			else 
			    r = mid - 1;
		} 
		cout << ans;
		return 0;
}
/*小心slz钟鼎皓或 上线盗你号 没小鸟的钟鼎皓盗我号骗分

*/