#include<bits/stdc++.h>
using namespace std;

signed main(){

  int64_t n,k;
  cin>>n>>k;
  vector<int64_t> a(n);
  for(auto& ai:a)cin>>ai;

  int64_t ans = 0;
  auto ok = [&](auto val){
    for(auto const& ai:a)if(ai<=val)return false;
    return true;
  };
  for(int i=0;i<n;++i){
    if(ok(k%a[i]))ans=max(ans,k%a[i]);
  }
  cout<<(ans)<<endl;

}