#ifndef ONLINE_JUDGE
#define _GLIBCXX_DEBUG
#endif
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using ll=long long;
using ld=long double;
using st=string;
using P=pair<ll,ll>;
typedef atcoder::modint mint;
ll inf=9e18;
template<typename T, int s, int i = 0>
auto vec(const ll (&sizes)[s], const T& init = T()){
  if constexpr(i < s) return vector(sizes[i], vec<T, s, i+1>(sizes, init));
  else return init;
}


int main(){
  ll l=0,r=1000000004,c,n,s;
  cin>>n>>s;
  auto v=vec<ll>({n},0);
  for(ll i=0;i<n;i++){
    cin>>v[i];
  }
  sort(v.rbegin(),v.rend());
  while(l+1<r){
    c=(l+r)/2;
    ll rem=s;
    for(ll i=0;i<n;i+=c){
      if(v[i]>c) rem-=v[i]+1;
      else {rem-=n-i;break;}
    }
    if(rem>=0) r=c;
    else l=c;
    // cout<<c<<" "<<rem<<"\n";
  }
  cout<<r<<"\n";
  
}