function IsTheMatrixCorrect(var MyFile: TextFile): Boolean;
var
   Number: Integer;
   TrueMatrix, IsValidInput: Boolean;
begin
   TrueMatrix := True;
   while (not Eof(MyFile)) do
   begin
      try
         read(MyFile, Number)
      except
         TrueMatrix := False
      end;
   end;
   if Eof(MyFile) then
      IsValidInput := True
   else
      Writeln('File is empty.');
   Reset(MyFile);
   IsTheMatrixCorrect := TrueMatrix;
end;