#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = unsigned;
using u64 = unsigned long long;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

int main() {
    double a, b, p, q, r;
    cin >> a >> b >> p >> q >> r;
    printf("%.10lf\n", b+(p*b-q*b+q*a)/(q+r));
    return 0;
}
