
let _ =
    let a, b, c = Scanf.scanf "%d %d %d" (fun a b c -> a, b, c) in
    let swap a b =
        if a < b then (a, b)
        else (b, a) in
    let a, b = swap a b in
    let b, c = swap b c in
    let a, b = swap a b in
    if a mod 2 = 1 && b mod 2 = 1 && c mod 2 == 1 then
        Printf.printf "%d\n" (a*b)
    else
        Printf.printf "0\n";;
