#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for(int i = 0; i < n; i++)
#define rep2(i, x, n) for(int i = x; i <= n; i++)
#define rep3(i, x, n) for(int i = x; i >= n; i--)
#define elif else if
#define sp(x) fixed << setprecision(x)
#define pb push_back
#define eb emplace_back
#define all(x) x.begin(), x.end()
#define sz(x) (int)x.size()
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
const ll MOD = 1e9+7;
//const ll MOD = 998244353;
const int inf = (1<<30)-1;
const ll INF = (1LL<<60)-1;
const ld EPS = 1e-10;
template<typename T> bool chmax(T &x, const T &y) {return (x < y)? (x = y, true) : false;};
template<typename T> bool chmin(T &x, const T &y) {return (x > y)? (x = y, true) : false;};

const int MAX_V = 20;
vector<vector<int>> combs[MAX_V+1]; //combs[i]:=N個からi個選ぶ全ての方法
vector<int> emp;
vector<int> memo;

void init(int n){
    combs[0].pb(emp);
    rep(i, n){
        for(auto &e: combs[i]){
            int j;
            if(e.empty()) j = -1;
            else j = e.back();
            rep2(k, j+1, n-1){
                memo = e, memo.pb(k);
                combs[i+1].pb(memo);
            }
        }
    }
}

int main(){
    int N, K;
    cin >> N >> K;
    init(N-1);
    int A[N];
    rep(i, N) cin >> A[i];
    sort(A, A+N, greater<int>());
    int ans = 0;
    rep2(i, 0, N-1){
        for(auto &e: combs[i]){
            int tmp = K;
            for(auto &u: e){
                tmp %= A[u];
            }
            tmp %= A[N-1];
            chmax(ans, tmp%A[N-1]);
        }
    }
    cout << ans << endl;
}