#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define rrep(i, n) for(int i=((int)(n)-1); i>=0; --i)
#define all(x) (x).begin(),(x).end()
#define MOD 1000000007
#define MOD2 998244353
#define INF 1000000007
#define LINF 1000000000000000007LL
#define PI 3.14159265359
#define P pair<ll,ll>
template <typename T>
inline bool chmax(T &a, const T &b){
  if(a<b) {a=b; return true;}
  else return false;
}
template <typename T>
inline bool chmin(T &a, const T &b){
  if(a>b) {a=b; return true;}
  else return false;
}
struct Edge{
  int to; ll cost;
  Edge(int to, ll cost) : to(to), cost(cost) {}
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;
void add_edge(Graph &g,int from,int to,ll cost,bool rev,ll rev_cost){
  g[from].push_back(Edge(to,cost));
  if(rev) g[to].push_back(Edge(from,rev_cost));
}



void solve(){
  int a,b;
  cin>>a>>b;
  int OR = a|b;
  ll ans=1;
  while(OR>0){
    ans*=OR;
    OR--;
  }
  cout<<ans<<'\n';
}

int main(){
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  cout<<setprecision(10)<<fixed;
  solve();
  return 0;
}