#include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> //#include<cctype> #include<climits> #include<iostream> #include<string> #include<vector> #include<map> //#include<list> #include<queue> #include<deque> #include<algorithm> //#include<numeric> #include<utility> //#include<memory> #include<functional> #include<cassert> #include<set> #include<stack> #include<random> const int dx[] = {1, 0, -1, 0}; const int dy[] = {0, -1, 0, 1}; using namespace std; typedef long long ll; typedef unsigned long long ull; typedef vector<int> vi; typedef vector<ll> vll; typedef pair<int, int> pii; int P0, Q; double p0, q; double dfs(int d, double p) { if (d == 24) return 0; double ret = 0; if (p == 0) { ret += 1/3. + dfs(d+1, p+q)/3; } else if (p == 1) { ret += 1/2. + dfs(d+1, p-q)/2; } else { // 使う ret += p/2 + p/2 * dfs(d+1, max(0.0, p-q)); ret += (1-p)/3 + (1-p)/3 * dfs(d+1, min(1.0, p+q)); } return ret; } int main() { cin >> P0 >> Q; p0 = P0/100., q = Q/100.; double ans = 1/3. + 1/3. * dfs(1, p0); printf("%.10lf\n", ans); return 0; }