#include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <algorithm>
#include <utility>
#include <queue>
#include <set>
#include <map>
#include <deque>
#include <iomanip>
#include <cstdio>
#include <stack>
#include <numeric>

using namespace std;
typedef  long long ll;
typedef pair<int,int> PII;
typedef vector<int> VI;
typedef vector<VI> VVI;
#define  MP make_pair
#define  PB push_back
#define inf  1000000007
#define rep(i,n) for(int i=0;i<(int)(n);++i)


int main(){
    double p,q;
    cin >> p >> q;
    p/=100.0;
    q/=100.0;
    cout.precision(20);
    cout << 100.0*p*q/(p*q+(1.0-p)*(1.0-q)) << endl;
    return 0;
}