program findDifference;
var
num, firstTwo, lastTwo, difference: integer;
begin
write('Enter a four-digit number: ');
readln(num);

firstTwo := num div 100;
lastTwo := num mod 100;

difference := (firstTwo div 10) - (lastTwo div 10);

writeln('The difference between the first two and last two digits is: ', difference);
end.