let rec synergy x =
    if (Array.length x) < 2 then x.(0)
    else x.(0) * (synergy (Array.sub x 1 ((Array.length x) - 1)));;

let factorial n =
    (synergy (Array.init n (fun x -> x + 1)));;

let rec pow x y =
    if y == 1 then x
    else x * (pow x (y - 1));;
    
print_endline @@ string_of_int @@ Scanf.scanf "%d" (fun x -> (factorial x) mod ((pow 10 9) + 7));;