var n,m,i,j,u,k,l:integer;
    x,arie,amax:longint;
    b:array[0..300,0..300] of longint;
    buf:array[1..100000]of char;
    f:text;
begin
  assign(f,'teren.in');reset(f);
  readln(f,n,m,x);
  settextbuf(f,buf);
  for i:=1 to n do
      for j:=1 to m do begin
        read(f,u);
{        a[i,j]:=u;}
        b[i,j]:=b[i-1,j]+b[i,j-1]-b[i-1,j-1]+u;
      end;
  close(f);
  amax:=0;
  for i:=1 to n do
     for j:=1 to m do
        for k:=i to n do
            for l:=j to m do
              if (b[k,l]-b[i-1,l]-b[k,j-1]+b[i-1,j-1]>x) then break
              else begin
                 arie:=(k-i+1)*(l-j+1);
                 if arie>amax then amax:=arie
              end;
  assign(f,'teren.out');
  rewrite(f);
  writeln(f,amax);
  close(f)
end.