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

typedef long long ll;

int main() {
    int N, K, X = 0;
    cin >> N >> K;
    vector<int> A(N);
    rep(i, N) cin >> A[i];
    sort(A.begin(), A.end());
    rep(i, N) {
        if (K % A[i] < A[0]) {
            X = max(X, K % A[i]);
        }
    }
    cout << X << "\n";
}