PROGRAM KeyGen;
USES wincrt;
VAR
    Key,User,Serial:string[20];
    i,x,P:integer;

BEGIN
    Key:='ABCDEYZ67FLMN012345X89OPQRSTUVWGHIJK';
    Writeln('      *** *** *** *** *** Mini Calc: Key Generator *** *** *** *** ***');
    Writeln('         -=-=-=-=-=-=-=-=-=- CodedBy: Z3r0n3 -=-=-=-=-=-=-=-=-=-=-=-=-');
    Writeln('                                 AT2000');
    Writeln('User Name:');
    Readln(User);
    Serial:='';
    FOR i:=0 TO Length(User)-1 DO
         BEGIN
              P:=i XOR 19;
              x:=Ord(User[i+1]) mod P;
              Serial:=Serial+Key[x+1];  
         END;
    Writeln('Serial: ',Serial);
END.