#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

const int N = 2e5+10;
int n, p;
ll a[N];

bool check(ll t) {
    ll rs = 0;
    for(int i=0; i<n; i++) {
        rs += t/a[i];
        if(rs >= p) return true;
    }
    return rs >= p;
}

int32_t main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> n >> p;
    for(int i=0; i<n; i++) {
        cin >> a[i];
    }
    ll l=0, r=1e18;
    ll rs=r;
    while(l<=r) {
        ll mid = (l+r)/2;
        if(check(mid)){
            rs=mid;
            r=mid-1;
        }
        else{
            l=mid+1;
        }
    }
    cout<<rs<<endl;

    return 0;
}