let a, b, c = Scanf.scanf " %d %d %d" @@ fun a b c -> a, b, c
let m, p = if a > b then if a > c then a, b * c else c, a * b else if b > c then b, a * c else c, a * b
let _ = Printf.printf "%d\n" @@ if a mod 2 = 0 || b mod 2 = 0 || c mod 2 = 0 then 0 else (m - m / 2 * 2) * p