/* template.cpp [[[ */
#include <bits/stdc++.h>
using namespace std;
#define get_macro(a, b, c, d, name, ...) name
#define rep(...) get_macro(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep(...) get_macro(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define rep1(n) rep2(i_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, b) rep4(i, a, b, 1)
#define rep4(i, a, b, s) for (ll i = (a); i < (ll)(b); i += (ll)s)
#define rrep1(n) rrep2(i_, n)
#define rrep2(i, n) rrep3(i, 0, n)
#define rrep3(i, a, b) rrep4(i, a, b, 1)
#define rrep4(i, a, b, s) for (ll i = (ll)(b) - 1; i >= (ll)(a); i -= (ll)s)
#define each(x, c) for (auto &&x : c)
#define fs first
#define sc second
#define all(c) begin(c), end(c)
using ui = unsigned;
using ll = long long;
using ul = unsigned long long;
using ld = long double;
const int inf = 1e9 + 10;
const ll inf_ll = 1e18 + 10;
const ll mod = 1e9 + 7;
const ll mod9 = 1e9 + 9;
const int dx[]{-1, 0, 1, 0, -1, 1, 1, -1};
const int dy[]{0, -1, 0, 1, -1, -1, 1, 1};
template<class T, class U> void chmin(T &x, const U &y){ x = min<T>(x, y); }
template<class T, class U> void chmax(T &x, const U &y){ x = max<T>(x, y); }
struct prepare_ { prepare_(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(12); } } prepare__;
ll in(){ ll x; cin >> x; return x; }
vector<ll> in(size_t n){ vector<ll> v(n); each(x, v) cin >> x; return v; }
/* ]]] */

int p0, q;
double dp[100010][110];

double dfs(int i, int p){
  double fp = p / 100.0;
  double fq = 1.0 - fp;
  if (i >= 100000) return 0.0;
  if (dp[i][p] >= 0) return dp[i][p];
  if (i == 0) return 1.0 / 3.0 + dfs(i + 1, p0) / 3.0;
  double ra = fp * (1.0 / 2.0 + dfs(i + 1, max(0, p - q)) / 2.0);
  double rb = fq * (1.0 / 3.0 + dfs(i + 1, min(100, p + q)) / 3.0);
  return dp[i][p] = ra + rb;
}

int main(){
  cin >> p0 >> q;
  fill_n(*dp, 1010 * 110, -1);
  cout << dfs(0, 0) << endl;
}