#include <bits/stdc++.h>
using namespace std;
class Solution {
 public:
  Solution(vector<pair<long long, long long>>& fences, long long a, long long b,
           long long sy)
      : segs(fences), pl(a), pr(b), py(sy) {
    int n = segs.size();
    sums.resize(n + 1);
    for (int i = 0; i < n; ++i) {
      sums[i + 1] = sums[i] + segs[i].second - segs[i].first;
    }
  }
  long double query(long long x, long long y) {
    long double fl = x + ((long double)y * (pl - x) / (y - py));
    long double fr = x + ((long double)y * (pr - x) / (y - py));
    int l = getGE(fl);
    int r = getGE(fr) - 1;
    long double res = 0;
    if (r >= l) {
      res = sums[r] - sums[l];
    }
    if (l - 1 >= 0 && r != l - 1) {
      res += max(0.0L, (long double)segs[l - 1].second - fl);
      if (segs[l - 1].first > fl) {
        cout << l - 1 << " " << segs[l - 1].first << " " << fl << endl;
      }
    }
    if (r >= 0) {
      res += max(0.0L, min(fr, (long double)segs[r].second) -
                           max(fl, (long double)segs[r].first));
    }
    res *= (long double)(y - py) / y;
    return res;
  }

 private:
  long long pl;
  long long pr;
  long long py;
  vector<pair<long long, long long>> segs;
  vector<long long> sums;
  int getGE(long double x) {
    auto it =
        lower_bound(segs.begin(), segs.end(), make_pair((long long)x, -1LL));
    int i = it - segs.begin();
    i = max(i - 2, 0);
    while (i < segs.size()) {
      if (segs[i].first >= x) {
        return i;
      }
      ++i;
    }
    return i;
  }
};
int main(int argc, char** argv) {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int sy, a, b;
  cin >> sy >> a >> b;
  int n;
  cin >> n;
  vector<pair<long long, long long>> segs;
  segs.reserve(n);
  for (int i = 0, l = 0, r = 0; i < n; ++i) {
    cin >> l >> r;
    segs.emplace_back(l, r);
  }
  Solution sol(segs, a, b, sy);
  int q;
  cin >> q;
  cout << fixed << setprecision(15);
  for (int i = 0, x = 0, y = 0; i < q; ++i) {
    cin >> x >> y;
    cout << sol.query(x, y) << endl;
  }
  return 0;
}
