#include <bits/stdc++.h>   using namespace std;   const long long INF = 1e18;   int32_t main() {     ios::sync_with_stdio(false);     cin.tie(0);     cout.tie(0);     long long n, m;     cin >> n >> m;     long long a[n], b[m];     for (long long i = 0; i < n; ++i) {       cin >> a[i];     }     for (long long i = 0; i < m; ++i) {       cin >> b[i];     }     long long ans = INF;     for (long long i = 0; i < n; ++i) {       long long res = -INF;       for (long long j = 0; j < n; ++j) {         if (i != j) {           for (long long k = 0; k < m; ++k) {             res = max(res, a[j] * b[k]);           }         }       }       ans = min(ans, res);     }     cout << ans;   }   