#include using namespace std; // #define int long long #define rep(i, n) for (long long i = (long long)(0); i < (long long)(n); ++i) #define reps(i, n) for (long long i = (long long)(1); i <= (long long)(n); ++i) #define rrep(i, n) for (long long i = ((long long)(n)-1); i >= 0; i--) #define rreps(i, n) for (long long i = ((long long)(n)); i > 0; i--) #define irep(i, m, n) for (long long i = (long long)(m); i < (long long)(n); ++i) #define ireps(i, m, n) for (long long i = (long long)(m); i <= (long long)(n); ++i) #define irreps(i, m, n) for (long long i = ((long long)(n)-1); i > (long long)(m); ++i) #define SORT(v, n) sort(v, v + n); #define REVERSE(v, n) reverse(v, v+n); #define vsort(v) sort(v.begin(), v.end()); #define all(v) v.begin(), v.end() #define mp(n, m) make_pair(n, m); #define cinline(n) getline(cin,n); #define replace_all(s, b, a) replace(s.begin(),s.end(), b, a); #define PI (acos(-1)) #define FILL(v, n, x) fill(v, v + n, x); #define sz(x) (long long)(x.size()) using ll = long long; using vi = vector; using vvi = vector; using vll = vector; using vvll = vector; using pii = pair; using pll = pair; using vs = vector; using vpll = vector>; using vtp = vector>; using vb = vector; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } template using vc=vector; template using vvc=vc>; const ll INF = 1e9+10; const ll MOD = 1e9+7; const ll LINF = 1e18; // ある二つの門を見る // その2つの門から逃亡する確率 // p1 + q1^2*p2*(2つの門の中を往復する確率の総和) // = p1 + q1^2*p2*(Σ(p1*p2)^k) // 無限等比級数なので、Σp(1*p2)^k=1/(1-p1*p2) // よって、ある二つの門からの逃亡確率p // p=p1 + q1^2*p2/(1-p1*p2) // 突破する確率q // q=q1*q2*(間を往復する確率の総和)=q1*q2/(1-p1*p2) signed main() { cin.tie( 0 ); ios::sync_with_stdio( false ); ll n; double p,q; cin>>n>>p>>q; if(p==1){ printf("%d\n", 1); return 0; } 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; } printf("%.15lf\n", P); }