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

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

    vector <int> ings(K);
    for (int i = 0; i < K; i++) {
        cin >> ings[i];
    }
    int max_price;
    for (int i = 0; i < R; i++) {
        int min_uses = 100000000;
        for (int j = 0; j < K; j++) {
            int amt;
            cin >> amt;
            if (amt != 0) {
                min_uses = min(min_uses, ings[j] / amt);
            }
        }
        int price;
        cin >> price;
        max_price = max(max_price, price * min_uses);
    }
    cout << max_price << endl;
    return 0;
}