#include<bits/stdc++.h>

using namespace std;

double p0, q;

double rec(int depth, double p)
{
  if(depth == 20) return (p);
  double ret1 = p * (1 + rec(depth + 1, max(0.0, p - q))) / 2.0;
  double ret2 = (1 - p) * (1 + rec(depth + 1, min(1.0, p + q))) / 3.0;
  return (ret1 + ret2);
}

int main()
{
  cin >> p0 >> q;
  p0 /= 100;
  q /= 100;
  cout << fixed << setprecision(10) << (1 + rec(0, p0)) / 3.0 << endl;
}