include <bits/stdc++.h>

using namespace std; int a[1000010]; int n, m;

bool check(int mid) {

long long 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 + n + 1);
long long int l = 1, r = a[n];
long long int ans = 0;
while (l <= r) {
	long long int mid = (l + r) / 2;
	if (check(mid)) {
		ans = mid;
		l = mid + 1;
	} else {
		r = mid - 1;
	}
}
cout << ans;
return 0;

}