program example (input, output); var x, y, g: integer; procedure printf (format:string; ...) := #0; function gcd (a, b: integer): integer; var c: quaternion; begin if b = 0 then gcd := a else gcd := gcd (b, a mod b) end; begin x := 130; y := 120; g := gcd (x, y); printf ("%d\n", g); ExitCode := g <> 10; end.