#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;
using LL = long long;
using ULL = unsigned long long;

int main() {
    int N, K;
    cin >> N >> K;

    int A[N];
    for (int i = 0; i < N; i++) {
        cin >> A[i];
    }

    vector<int> v;
    for (int i = 0; i < N; i++) {
        v.push_back(i);
    }

    int ans = 0;
    while (next_permutation(v.begin(), v.end())) {
        int k = K;
        for (int i = 0; i < v.size(); i++) {
            k %= A[v[i]];
        }
        ans = max(ans, k);
    }

    cout << ans << endl;
}