#include <bits/stdc++.h>

using namespace std;

int main() {
    long long k, r;
    cin >> k >> r;
    long long budget[k+5];
    for(int i=1;i<=k;i++) cin >> budget[i];
    long long ans = 0;
    
    int cost_j;
    for(int i=1;i<=r;i++) {
        long long mx = 999999999999LL;
        for(int j=1;j<=k;j++) {
            cin >> cost_j;
            if(cost_j == 0) mx = 0;
            else mx = min(mx, budget[j] / cost_j);
        }
        long long rev = 0;
        cin >> rev;
        ans = max(ans, mx * rev);
    }
    cout << ans << endl;
}