#include <bits/stdc++.h>
using namespace std;
int main() {
  long long i, j, m, a, s, c, b, n, x, y, ar[1001];
  cin >> n;
  while (n--) {
    cin >> s >> a >> b >> c;
    x = s / c;
    y = x / a * b;
    cout << x + y << endl;
  }
  return 0;
}
