C++ :

#include <bits/stdc++.h>
using namespace std;
long long n, m, a, b;
bool check(long long t){
    if ((a + b) * t > n + m)
        return false;
    if (a == b){
        if (a * t <= n && a * t <= m)
            return true;
        else
            return false;
    }
    double low, high;
    if (a > b){
        low = (1.0 * a * t - m) / (a - b);
        high = (1.0 * n - b * t) / (a - b);
    }
    else{
        low = (1.0 * n - b * t) / (a - b);
        high = (1.0 * a * t - m) / (a - b);
    }
    long long L = ceil(low);
    long long R = floor(high);
    L = max(L, (long long)0);
    R = min(R, t);
    return (L <= R);
}
int main(){
    cin >> n >> m;
    cin >> a >> b;
    long long ans = 0;
    long long left = 0;
    long long right = max(n, m) / min(a, b) + 1;
    while (left <= right){
        long long mid = (left + right) / 2;
        if (check(mid)){
            ans = mid;
            left = mid + 1;
        }
        else{ 
            right = mid - 1;
        }
    }
    cout << ans;
    return 0;
}