#include <bits/stdc++.h>
using namespace std;
double y, a, b;
int n1, n2;
const double eps = 1e-9;
pair<int, int> engel[200007];
map<int, int> pre;
double kesis(double a1, double a2, double b1, double b2) {
  if (a1 >= b2 || b1 >= a2) return 0;
  if ((a1 <= b1 && a2 >= b2) || (b1 <= a1 && b2 >= a2))
    return min(a2 - a1, b2 - b1);
  if (a1 <= b1) return a2 - b1;
  return b2 - a1;
}
double solve(double xx, double yy) {
  double l = xx - ((xx - a) / (yy - y) * yy),
         r = xx - ((xx - b) / (yy - y) * yy);
  int ll = 0, rr = n1 - 1, m;
  int la = -1e9 - 100;
  while (ll <= rr) {
    m = (ll + rr) / 2;
    if (engel[m].first <= l) {
      ll = m + 1;
      la = max(la, m);
    } else
      rr = m - 1;
  }
  int k1 = max(la, -1);
  ll = 0;
  rr = n1 - 1;
  la = 1e9 + 10;
  while (ll <= rr) {
    m = (ll + rr) / 2;
    if (engel[m].second >= r) {
      rr = m - 1;
      la = min(la, m);
    } else
      ll = m + 1;
  }
  int k2 = la;
  k2 = min(k2, n1);
  double ans = 0;
  if (k1 != k2) ans = pre[k2 - 1] - pre[k1];
  if (k1 != -1) ans += kesis(l, r, engel[k1].first, engel[k1].second);
  if (k2 != n1) ans += kesis(l, r, engel[k2].first, engel[k2].second);
  if (k1 == k2 && k1 != -1 && k1 != n1)
    ans -= kesis(l, r, engel[k2].first, engel[k2].second);
  return ans * (b - a) / (r - l);
}
int main() {
  scanf("%lf %lf %lf", &y, &a, &b);
  scanf("%d ", &n1);
  int i;
  int l = 0;
  for (i = 0; i < n1; i++) {
    scanf("%d %d", &engel[i].first, &engel[i].second);
    l += engel[i].second - engel[i].first;
    pre[i] = l;
  }
  scanf("%d ", &n2);
  double x, y;
  for (i = 0; i < n2; i++) {
    scanf("%lf %lf", &x, &y);
    printf("%.12lf\n", solve(x, y));
  }
  return 0;
}
