#include <bits/stdc++.h>
using namespace std;
int main()
{
    int n,m,a[25][25],ans=0x7f7f7f7f;
    cin>>n>>m;
    for (int i=1;i<=n;++i) for (int j=1;j<=m;++j) cin>>a[i][j];
    for (int i = 1; i <= n; ++i)
      for (int j = 1; j <= m; ++j)
        for (int x = i; x <= n; ++x)
          for (int y = j; y <= m; ++y) {
            int sum = 0;
            for (int p = i; p <= x; ++p) 
              for (int q = j; q <= y; ++q)
                if (a[p][q]==1) sum++;
                if (sum >= x) ans = min(ans, (x - i + 1) * (y - j + 1));
          }
    cout<<ans;
}