#include <bits/stdc++.h>
using namespace std;
struct Segment {
  double l, r;
};
vector<Segment> segments;
vector<long long> segSum;
double findOverlap(double l, double r) {
  int s1l = 0, s1r = segments.size() - 1, s1m;
  while (s1l < s1r) {
    s1m = (s1l + s1r) / 2;
    if (segments[s1m].r < l)
      s1l = s1m + 1;
    else
      s1r = s1m;
  }
  int s2l = 0, s2r = segments.size() - 1, s2m;
  while (s2l < s2r) {
    s2m = (s2l + s2r) / 2;
    if (segments[s2m].r < r)
      s2l = s2m + 1;
    else
      s2r = s2m;
  }
  double s = s2l > 0 && s2l > s1l ? segSum[s2l - 1] - segSum[s1l] : 0;
  s += max(0.0, min(r, segments[s1l].r) - max(l, segments[s1l].l));
  if (s1l != s2l)
    s += max(0.0, min(r, segments[s2l].r) - max(l, segments[s2l].l));
  return s;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  double sy, a, b;
  int q, n;
  cin >> sy >> a >> b >> n;
  for (int i = 0; i < n; i++) {
    int l, r;
    cin >> l >> r;
    segments.push_back({.l = (double)l, .r = (double)r});
    segSum.push_back((i > 0 ? segSum[i - 1] : 0) + r - l);
  }
  cin >> q;
  for (int i = 0; i < q; i++) {
    int x, y;
    double l, r;
    cin >> x >> y;
    l = a - sy / (y - sy) * (x - a);
    r = b - sy / (y - sy) * (x - b);
    double z = findOverlap(l, r) / (r - l) * (b - a);
    printf("%.15f\n", z);
  }
  return 0;
}
