#include<bits/stdc++.h>
// #include<atcoder/all>
using namespace std;
// using namespace atcoder;
using lint = long long;
using graph = vector<vector<int>>;
#define endl '\n'
lint const mod = 1e9+7;
//long const mod = 998244353;


int main(){
    int n,k;
    int a[n];
    cin >> n >> k;
    for(int i=0;i<n;i++)cin >> a[i];
    int ans = 0;
    sort(a,a+n);
    vector<unordered_set<int>>dp(1<<n);
    queue<int>que;
    que.push(0);
    dp[0].insert(k);
    for(int bit = 1;bit< (1<<k);bit+=2){
        int tmp = k;
        for(int i=k-1;k>=0;k--){
            if(bit & (1<<i)){
                tmp %= a[i];
            }
        }
        ans  = max(ans,tmp);
    }
    cout << ans << endl;
}