#include<bits/stdc++.h>
using namespace std;
using LL = long long;
using ULL = unsigned long long;
#define rep(i,n) for(int i=0; i<(n); i++)

int N,K;
int A[20];

int main() {
  cin>>N>>K; rep(i,N) cin>>A[i]; sort(A,A+N,greater<int>());
  vector<int> V={K};
  rep(i,N-1) rep(j,1<<i) V.push_back(V[j]%A[i]);
  int ans=0; for(int v:V) ans=max(ans,v%A[N-1]);
  cout<<ans<<endl;
  return 0;
}