#include #include #include using namespace atcoder; using mint = modint998244353; using namespace std; #define rep(i,n) for(int i=0;i<(n);i++) #define Inf 1000000000 struct combi{ deque kaijou; deque kaijou_; combi(int n){ kaijou.push_back(1); for(int i=1;i<=n;i++){ kaijou.push_back(kaijou[i-1]*i); } mint b=kaijou[n].inv(); kaijou_.push_front(b); for(int i=1;i<=n;i++){ int k=n+1-i; kaijou_.push_front(kaijou_[0]*k); } } mint combination(int n,int r){ if(r>n)return 0; mint a = kaijou[n]*kaijou_[r]; a *= kaijou_[n-r]; return a; } mint junretsu(int a,int b){ mint x = kaijou_[a]*kaijou_[b]; x *= kaijou[a+b]; return x; } mint catalan(int n){ return combination(2*n,n)/(n+1); } }; int main(){ int N,A,B; cin>>N>>A>>B; mint p = A; p /= B; vector> t(2); t[0] = {0,1}; t[1] = {1,0}; rep(i,N){ vector> temp(2); rep(i,2){ temp[i] = convolution(t[i],t[i]); } auto tt = convolution(t[0],t[1]); rep(j,tt.size())tt[j] *= 2; rep(j,tt.size()){ temp[0][j] += tt[j] * p; temp[1][j] += tt[j] * (1-p); } swap(t,temp); } combi C(1000000); vector P(1<