#include<iostream>
#include<fstream>
#include<algorithm>
using namespace std;
	ifstream fin("eko.in");
	ofstream fout("eko.out");
int n,m;
int a[1000000]={0};
bool check(int x){
	int s=0;
	for(int i=0;i<n;i++){
		if(a[i]>x)
			s+=a[i]-x;
	}
	return s>=m;
}
int solve(){
	int left=0,right=a[n-1]+30,mid;//fout<<a[n-1]<<endl;
	while(left+1<right){
		mid=(left+right)/2;
		if(check(mid)) left=mid;
		else right=mid;
	}
	if(check(left)) return left;
	else return right;
}
int main()
{
	fin>>n;
	fin>>m;
	for(int i=0;i<n;i++)
		fin>>a[i];
	sort(a+0,a+n);
	fout<<solve()<<endl;
	fin.close();
	fout.close();
return 0;
}