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// PA2017, Iloczyn
// Andrzej Pezarski

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int K;
long long N;
vector<long long> V;
vector<long long> W;

long long cnt=0;
long long RES=1;


void zlicz0() {
    vector<long long> P(K);
    for(auto &p:P) cin >> p;
    for(auto p:P) {
        while (p<=N) {
            V.push_back(p);
            if (p>1000000000) break;
            p*=p;
        }
    }
    sort(V.begin(), V.end());
}



void zlicz1(long long X, long long N0, int i) {
    if (X<=N0) W.push_back(X);
    cnt++;
    for (int j=i; j<V.size(); j++){
        if (X>N0/V[j]) break;
        zlicz1(X*V[j], N0, j+1);
    }
}


void zlicz2(long long X, long long N0, int i) {
    if (X>N0) return;
    auto it=upper_bound(W.begin(), W.end(), N/X);
    if (it!=W.begin()) {
        it--;
        RES=max(RES, X*(*it));
    }
    for (int j=i; j<V.size(); j++){
        if (X>N0/V[j]) break;
        zlicz2(X*V[j], N0, j+1);
    }
}

int main() {
    cin >> K >> N;
    zlicz0();

    if (N<=1000000000) {
        W.push_back(1);
        zlicz2(1, N, 0);
    } else {
        zlicz1(1, 10000000, 0);
        sort(W.begin(), W.end());
        zlicz2(1, N/500000, upper_bound(V.begin(), V.end(), 15)-V.begin());
//        zlicz2(1, N/1000000, 0);
    }
    
    cout << RES << endl;
    
    return 0;
}