program Tuoi;
uses crt;
var i: integer;
Begin
clrscr;
write('Nhap tuoi cua ban'); readln(i);
if (i<18) then writeln('Ban la thieu nien')
else if (i>=18) and (i<=39) then writeln('Ban la thanh nien')
else if (i>=40) and (i<=60) then writeln('Ban la trung nien')
else writeln('Ban la lao nien');
readln;
End.