#include <iostream>
#include <fstream>
using namespace std;
ifstream in("teren.in");
ofstream out("teren.out");
const int maxn = 305;
int sp[maxn][maxn];
int main()
{
    int n, m, k;
    in >> n >> m >> k;
    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= m; j++)
        {
            bool x;
            in >> x;
            sp[i][j] = sp[i-1][j] + x;
        }
    }
    int mx = 0;
    for(int linst = 1; linst <= n; linst++)
    {
        for(int linfn = linst; linfn <= n; linfn++)
        {
            int st = 1;
            int sum = 0;
            for(int dr = 1; dr <= m; dr++)
            {
                int p = sp[linfn][dr] - sp[linst - 1][dr];
                sum = sum + p;
                while(st <= dr && sum > k)
                {
                    sum  = sum - (sp[linfn][st] - sp[linst - 1][st]);
                    st++;
                }
                if(sum <= k)
                    mx = max(mx, (dr - st + 1) * (linfn - linst + 1));
            }
        }
    }
    out << mx << "\n";
    return 0;
}