#define _USE_MATH_DEFINES #include "bits/stdc++.h" using namespace std; #define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i)) #define rep(i,j) FOR(i,0,j) #define each(x,y) for(auto &(x):(y)) #define mp make_pair #define MT make_tuple #define all(x) (x).begin(),(x).end() #define debug(x) cout<<#x<<": "<<(x)<; using vi = vector; using vll = vector; void solve() { int N; double p, q; cin >> N >> p >> q; if (abs(1 - p) < 1e-10) { cout << 1 << endl; return; } double P = p, Q = q; rep(i, N - 1) { double PP = P + Q * Q*p / (1 - P * p); Q = Q * q / (1 - P * p); P = PP; } cout << P << endl; } int main() { ios::sync_with_stdio(false); cin.tie(0); cout << fixed << setprecision(15); solve(); return 0; }