#include <bits/stdc++.h> #include <atcoder/modint> using namespace atcoder; //#pragma GCC optimize ("O3") using namespace std; #define reps(i,s,n) for(int i = s; i < n; i++) #define rep(i,n) reps(i,0,n) #define Rreps(i,n,e) for(int i = n - 1; i >= e; --i) #define Rrep(i,n) Rreps(i,n,0) #define ALL(a) a.begin(), a.end() using ll = long long; using vec = vector<ll>; using mat = vector<vec>; ll N,M,H,W,Q,K,A,B; string S; using P = pair<ll, ll>; using tp = tuple<ll, ll, ll>; const ll INF = (1LL<<60); template<class T> bool chmin(T &a, const T b){ if(a > b) {a = b; return true;} else return false; } template<class T> bool chmax(T &a, const T b){ if(a < b) {a = b; return true;} else return false; } template<class T> void my_printv(std::vector<T> v,bool endline = true){ if(!v.empty()){ for(std::size_t i{}; i<v.size()-1; ++i) std::cout<<v[i]<<" "; std::cout<<v.back(); } if(endline) std::cout<<std::endl; } using mint = modint998244353; using vm = vector<mint>; int main() { cin.tie(nullptr); ios::sync_with_stdio(false); cin>>N>>M; ll res = 1; rep(i, (N | M)) res *= i + 1; cout<<res<<endl; }