#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define rep(i,n) for(int i=0;i<n;i++)
#define drep(i,n) for(int i=n-1;i>=0;i--)
#define vec(...) vector<__VA_ARGS__>
#define _3aILRlt ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
using namespace std;
using ll=long long;
using pii=pair<int,int>;
using tpii=pair<pii,int>;
using vi=vector<int>;

int main(){
_3aILRlt;
	int a,b;
	cin>>a>>b;
	int c=a | b;
	ll ans=1;
	for(int x=2;x<=c;x++){
		ans*=x;
	}
	cout<<ans<<"\n";
//	
	return 0;
}