#include<bits/stdc++.h>
using namespace std;
const int N = 1000010;
long long n, m, a[N];
long long mid, l = 0, r = 1e9, num;
int find(int k){
	while(l <= r){
		int ans = 0;
		mid = (l+r) >> 1;
		for(int i = 1;i <= n;i++){
			if(a[i] > k){
				ans += a[i] - k;
			}
		}
		if(ans >= k){
			num = mid;
			l = mid + 1;
		}
		else{
			r = mid - 1;
		}
	}
	return num;
}

int main(){
	cin >> n >> m;
	for(int i = 1;i <= n;i++){
		cin >> a[i];
	}
	sort(a+1, a+n+1);
	cout << find(m);
	return 0;
}