program mwt;
var
s:array[0..200,0..200]of real;
b,c,d:array[1..40000]of longint;
t,i,j,n,m,l,g:longint;
sum,x:real;

procedure qk(l,r:longint);
var i,j,m,t:longint;
begin
i:=l;j:=r;m:=d[(l+r)div 2];
repeat
while d[i]>m do inc(i);
while d[j]<m do dec(j);
if i<=j then
   begin
    t:=d[i];
    d[i]:=d[j];
    d[j]:=t;
    t:=c[i];
    c[i]:=c[j];
    c[j]:=t;
    t:=b[i];
    b[i]:=b[j];
    b[j]:=t;
    inc(i);
    dec(j);
   end;
until i>j;
if i<r then qk(i,r);
if j>l then qk(l,j);
end;

begin
assign(input,'long.in');reset(input);
assign(output,'long.out');rewrite(output);
readln(n,m);
t:=0;
for i:=1 to n do
begin
   sum:=0;
   for j:=1 to m do
    begin
     read(x);
     s[i,j]:=s[i-1,j]+s[i,j-1]-s[i-1,j-1]+x;
     inc(t);
     b[t]:=i;c[t]:=j;d[t]:=i*j;
    end;
   end;
qk(1,t);
for l:=1 to t do
begin
   for i:=1 to n-b[l]+1 do
    for j:=1 to m-c[l]+1 do
     begin
      sum:=s[i+b[l]-1,j+c[l]-1]-s[i+b[l]-1,j-1]-s[i-1,j+c[l]-1]+s[i-1,j-1];
      if sum>0 then
       begin
        writeln(d[l]);
        close(input);close(output);
        halt;
       end;
      end;
   end;
writeln(0);
close(input);close(output);
end.