import java.util.*;

public class Main{
  
  public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
    
    int a = sc.nextInt();
    int b = sc.nextInt();
    
    int bsum = a | b;
    
    long ans = 1;
    
    for(int i=1; i<=bsum; i++){
      ans *= i;
    }
    
    System.out.println(ans);
  
  }

}