#include<bits/stdc++.h>
#define ll long long
using namespace std;
long long m,n,a[1000009];
long long l=0,r=0;
int main(){
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		r=max(r,a[i]);
	}
	while(l<=r){
		int mid=(l+r)/2;
		int count=0;
		for(int i=1;i<=n;i++){
			if(a[i]>mid) count+=a[i]-mid;
		}
		if(count<m) r=mid-1;
		else l=mid+1;
	}
	cout<<l-1<<endl;
	return 0;
}