program long(input,output);

var
  m,n,i,j,ii,jj,k,ans,max,tmp:longint;
  pre:array[0..200,0..200]of longint;
  map:array[0..200,0..200]of longint;

begin
  assign(input,'long.in');
  reset(input);
  assign(output,'long.out');
  rewrite(output);

  readln(n,m);
  for i:=1 to n do
    for j:=1 to m do
    begin
      read(map[i,j]);
      pre[i,j]:=pre[i,j-1]+pre[i-1,j]-pre[i-1,j-1]+map[i,j];
    end;

  for i:=1 to n do
     for j:=1 to m do
       for k:=0 to n do
       begin
         ii:=i+k;
         jj:=i+k;

         if (ii>n) or (jj>n) then
           break;

         tmp:=pre[ii,jj]-(pre[i-1,jj]+pre[ii,j-1])+pre[i-1,j-1];
         if tmp>max then
         begin
           max:=tmp;
           ans:=(k+1)*(k+1);
         end;
       end;

  writeln(ans);

  close(input);
  close(output);
end.