#include <bits/stdc++.h>
using namespace std;
long long modulo(long long base, long long exponent, long long modulus);
long long choose(long long n, long long k);
long long inverse(long long a, long long m);
void build();
void fileio();
long long ncr(long long n, long long r);
const int nax = 1e6 + 10;
const int LG = log2(nax) + 1;
vector<long long> fact(nax);
double dp[2][1005][1005];
double dpsolve(long long turn, double w, double b) {
  if (w < 0 || b < 0) return 0;
  if ((w + b) == 0) return 0;
  double &ans = dp[turn][(int)w][(int)b];
  if (ans != -1) return ans;
  ans = 0;
  double n = (1.0 * w) / (w + b);
  double m = (1.0 * b) / (w + b);
  if (!turn) {
    ans = n + m * dpsolve(!turn, w, b - 1);
  } else {
    if (w + b != 1)
      ans += m * ((b - 1) / (w + b - 1) * dpsolve(!turn, w, b - 2) +
                  (w / (w + b - 1)) * dpsolve(!turn, w - 1, b - 1));
  }
  return ans;
}
int32_t main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  long long w, b;
  cin >> w >> b;
  for (int i = 0; i < 2; i++)
    for (int j = 0; j < 1005; j++)
      for (int k = 0; k < 1005; k++) dp[i][j][k] = -1;
  cout << fixed << setprecision(9);
  cout << dpsolve(0, w, b) << '\n';
  return 0;
}
long long ncr(long long n, long long r) {
  if (r > n || r < 0 || n < 0) return 0;
  long long ans = fact[n];
  long long temp = (fact[n - r] * fact[r]) % 1000000007;
  ans = (ans * inverse(temp, 1000000007)) % 1000000007;
  return ans;
}
void fileio() {
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
}
void build() {
  fact[0] = 1;
  for (long long i = 1; i < nax; i++) fact[i] = (fact[i - 1] * i) % 1000000007;
}
long long modulo(long long base, long long exponent, long long modulus) {
  if (modulus == 1) return 0;
  long long result = 1;
  base = base % modulus;
  while (exponent > 0) {
    if (exponent % 2 == 1) {
      result = (result * base) % modulus;
    }
    exponent = exponent >> 1;
    base = (base * base) % modulus;
  }
  return result;
}
long long choose(long long n, long long k) {
  if (k == 0) return 1;
  return (n * choose(n - 1, k - 1)) / k;
}
void EE(long long a, long long b, long long &co1, long long &co2) {
  if (a % b == 0) {
    co1 = 0;
    co2 = 1;
    return;
  }
  EE(b, a % b, co1, co2);
  long long temp = co1;
  co1 = co2;
  co2 = temp - co2 * (a / b);
}
long long inverse(long long a, long long m) {
  long long x, y;
  EE(a, m, x, y);
  if (x < 0) x += m;
  return x;
}
