(use util.combinations) (define yuki420 (let* ( (x (read)) (comb (lambda (a b) (length (combinations (iota a) b)))) (s (- (expt 2 31) 1)) ) (display (comb 31 x)) (display " ") (display (if (zero? x) 0 (* s (comb 30 (- x 1))) ) ) (newline) ) )