Program Rekursi Faktorial

uses wincrt;
var
x:integer;
function faktorial(M:integer):longint;
begin
if M=0 then
faktorial:=1
else
faktorial:=M*faktorial(M-1);
end;
begin
clrscr;
write('masukkan nilai: ');read(x);
writeln;
write(x,'! = ',faktorial(x));
readln;
end.