#include <fstream>
using namespace std;
ifstream cin("teren.in");
ofstream cout("teren.out");
bool a[305][305];
int n,m,x,Min,dim,i,j,s[305][305],first,last;
int main()
{
    cin>>n>>m>>x;
    for(i=1;i<=n;i++)
        for(j=1;j<=m;j++){
            cin>>a[i][j];
            s[i][j]=s[i-1][j]+a[i][j];
        }
    for(i=1;i<=n;i++){
        for(j=i;j<=n;j++){
            first=1;
            int sum=0;
            for(last=1;last<=m;last++){
                sum+=(s[j][last]-s[i-1][last]);
                while(sum>x&&first<=last){
                    sum-=(s[j][first]-s[i-1][first]);
                    first++;
                }
                if(first<=last&&sum<=x&&(j-i+1)*(last-first+1)>=dim)
                    dim=(j-i+1)*(last-first+1);
            }
        }
    }
    cout<<dim;
    return 0;
}