// No.1713 trick or treat!
package main

import "fmt"

func main() {
	var t1, t2 int
	fmt.Scan(&t1, &t2)

	var ans = (t1 | t2)
	for i := (t1 | t2) - 1; i > 0; i-- {
		ans *= i
	}
	fmt.Println(ans)
}