#include<bits/stdc++.h>
using namespace std;
using ll = long long;

int main() {
  ios::sync_with_stdio(false), cin.tie(0);
  int x, pp; cin >> x >> pp;
  double p = pp / 100.0;
  double ans;
  if(x % 2) {
    ans = 1 + (1 / p) * (x / 2) + (1 / p) * (1 - p);
  } else {
    ans = (1 / p) * (x / 2);
  }
  cout << fixed << setprecision(7) << ans << endl;
}
