var f,g:text;
    v:array[0..310,0..310]of longint;
    s:array[0..310]of longint;
    n,m,x,i,j,max,p,y,w:longint;

begin
assign(f,'teren.in');
assign(g,'teren.out');
reset(f);
rewrite(g);
read(f,n,m,x);
for i:=1 to n do
  for j:=1 to m do read(f,v[i,j]);
for i:=1 to n do
  for j:=1 to m do
    v[i,j]:=v[i,j]+v[i-1,j]+v[i,j-1]-v[i-1,j-1];
for i:=1 to n do
  for j:=i to n do
    begin
      p:=1;
      for y:=1 to m do
        begin
          s[y]:=s[y-1]+v[j,y]-v[i-1,y]-v[j,y-1]+v[i-1,y-1];
          while (s[y]>x)and(p<=y)do
            begin
              dec(s[y],v[j,p]-v[i-1,p]-v[j,p-1]+v[i-1,p-1]);
              inc(p);
            end;
          if ((j-i+1)*(y-p+1)>max)then max:=(j-i+1)*(y-p+1);
        end;
    end;
write(g,max);
close(f);
close(g);
end.