#include <bits/stdc++.h>
#include <string>
#define ft first
#define sc second
#define pt(sth) cout << sth << "\n"
#define chmax(a, b) (a)=max(a, b);
#define chmin(a, b) (a)=min(a, b);
#define moC(a, s, b) (a)=((a)s(b)+MOD)%MOD
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pll;
static const ll INF=1e18;
static const ll MAX=101010;
static const ll MOD=1e9+7;


/*
 for(i=0; i<N; i++)
   cin >> a[i];
*/




int main(void) {
  ll i, j, k;
  
  double p, q;
  cin >> p >> q;
  p/=100; q/=100;
  printf("%.10f\n", 100*p*q/(p*q+(1-p)*(1-q)));
  
  
}