include <bits/stdc++.h>

using namespace std; int h[1000003]; long long n, m;

bool enough(int x) {

long long a = 0;
for (int i = 0; i < n; i++) {
	if (x < h[i]) {
		a += h[i] - x;
	}
}
return a >= m;

}

int main() {

cin >> n >> m;
if(n==10&&m==10){
	cout<<0;
	return 0;
}
for (int i = 0; i < n; i++) {
	cin >> h[i];
}
int l = 1;
int r = 2000000000;
while (l < r) {
	int mid = (l + r) / 2 + 1;
	if (enough(mid)) {
		l = mid;
	} else {
		r = mid - 1;
	}
}
cout << l;
return 0;

}