var a,b:real;
begin
writeln ('Ââåäèòå öåíó íà êíèãó');
read (a);
writeln ('Ââåäèòå ñóììó âíåñåííóþ ïîêóïàòåëåì');
read (b);
if b>a then writeln ('Âàøà ñäà÷à ',b-a) 
else if b=a then writeln ('Ñïàñèáî !');
end.