Kaprekar Number

program KaprekarNumbers;

uses sysutils;

var
  userNumber, squareNumber: string;

begin
  writeln('Enter a number:');
  readln(userNumber);
  squareNumber := inttostr(sqr(strtoint(userNumber)));
  if strtoint(copy(squareNumber, 1, length(squareNumber) - length(userNumber))) + strtoint(copy(squareNumber, length(squareNumber) - length(userNumber) + 1, length(userNumber) + 1)) = strtoint(userNumber) then
    writeln('Kaprekar number!')
  else
    writeln('Not a kaprekar number!');
  readln;
end.