#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization("unroll-loops")
using namespace std;
const long long MOD = 1e+9 + 7;
const long long INF = 0x7f7f7f7f7f7f7f7f;
const int INFi = 0x7f7f7f7f;
const long long MAXN = 1e+5 + 7;
vector<long long> adj[MAXN];
long long visit[MAXN] = {};
int dx8[] = {0, 1, 1, 1, 0, -1, -1, -1}, dy8[] = {1, 1, 0, -1, -1, -1, 0, 1};
int dx4[] = {0, 1, 0, -1}, dy4[] = {1, 0, -1, 0};
int t = 1;
long long b, w;
long double dp[1005][1005] = {};
map<pair<long long, long long>, long double> memo;
long double solve(long long w, long long b) {
  if (w <= 0) return 0;
  if (b <= 0) return 1;
  pair<long long, long long> args = make_pair(w, b);
  if (memo.find(args) != memo.end()) {
    return memo[args];
  }
  long double ret = (long double)((long double)(w) / (long double)(w + b));
  long double cont_prob =
      (long double)((long double)(b) / (long double)(w + b));
  b--;
  cont_prob *= (long double)((long double)(b) / (long double)(w + b));
  b--;
  if (cont_prob > 1e-13) {
    long double push_back =
        solve(w, b - 1) * (long double)((long double)b / (long double)(w + b));
    long double pw =
        solve(w - 1, b) * (long double)((long double)w / (long double)(w + b));
    ret += (long double)cont_prob * ((long double)(push_back + pw));
  }
  return memo[args] = ret;
}
void MAIN() {
  cin >> w >> b;
  for (long long i = 0; i <= 1000; i++) {
    for (long long j = 0; j <= 1000; j++) dp[i][j] = -1;
  }
  cout << solve(w, b);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout << fixed;
  cout << setprecision(10);
  ;
  mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
  ;
  while (t--) {
    MAIN();
  }
}
