#include <bits/stdc++.h>
#pragma GCC target("avx")
#pragma GCC optimize(3)
#pragma GCC optimize("Ofast")
#pragma GCC optimize("inline")
#pragma GCC optimize("-fgcse")
#pragma GCC optimize("-fgcse-lm")
#pragma GCC optimize("-fipa-sra")
#pragma GCC optimize("-ftree-pre")
#pragma GCC optimize("-ftree-vrp")
#pragma GCC optimize("-fpeephole2")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-fsched-spec")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-falign-jumps")
#pragma GCC optimize("-falign-loops")
#pragma GCC optimize("-falign-labels")
#pragma GCC optimize("-fdevirtualize")
#pragma GCC optimize("-fcaller-saves")
#pragma GCC optimize("-fcrossjumping")
#pragma GCC optimize("-fthread-jumps")
#pragma GCC optimize("-funroll-loops")
#pragma GCC optimize("-fwhole-program")
#pragma GCC optimize("-freorder-blocks")
#pragma GCC optimize("-fschedule-insns")
#pragma GCC optimize("inline-functions")
#pragma GCC optimize("-ftree-tail-merge")
#pragma GCC optimize("-fschedule-insns2")
#pragma GCC optimize("-fstrict-aliasing")
#pragma GCC optimize("-fstrict-overflow")
#pragma GCC optimize("-falign-functions")
#pragma GCC optimize("-fcse-skip-blocks")
#pragma GCC optimize("-fcse-follow-jumps")
#pragma GCC optimize("-fsched-interblock")
#pragma GCC optimize("-fpartial-inlining")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("-freorder-functions")
#pragma GCC optimize("-findirect-inlining")
#pragma GCC optimize("-fhoist-adjacent-loads")
#pragma GCC optimize("-frerun-cse-after-loop")
#pragma GCC optimize("inline-small-functions")
#pragma GCC optimize("-finline-small-functions")
#pragma GCC optimize("-ftree-switch-conversion")
#pragma GCC optimize("-foptimize-sibling-calls")
#pragma GCC optimize("-fexpensive-optimizations")
#pragma GCC optimize("-funsafe-loop-optimizations")
#pragma GCC optimize("inline-functions-called-once")
#pragma GCC optimize("-fdelete-null-pointer-checks")
using namespace std;
int n, m, Q;
double sy, l[200100], r[200100], sum[200100], zl, zr, x, y, ans;
struct Node {
  double x, y;
} bj[2][200100], tmp, L, R;
inline bool lef(Node u, Node v, Node w) {
  if (u.x == v.x) return w.x < u.x;
  double t;
  t = v.x - (v.x - u.x) * (v.y - w.y) / (v.y - u.y);
  return w.x < t;
}
inline double ask(int u) {
  double p, q;
  if (bj[0][u].x == x)
    p = x;
  else {
    p = x - (x - bj[0][u].x) * (y - sy) / y;
  }
  if (bj[1][u].x == x)
    q = x;
  else {
    q = x - (x - bj[1][u].x) * (y - sy) / y;
  }
  return max((double)0, min(q, zr) - max(p, zl));
}
int main() {
  int i, j, p, q, mid, a, b;
  cin >> sy >> zl >> zr >> n;
  L.y = R.y = sy, L.x = zl, R.x = zr;
  for (i = 1; i <= n; i++) {
    scanf("%lf%lf", &l[i], &r[i]);
    sum[i] = sum[i - 1] + r[i] - l[i];
    bj[0][i].y = 0, bj[0][i].x = l[i];
    bj[1][i].y = 0, bj[1][i].x = r[i];
  }
  cin >> m;
  for (i = 1; i <= m; i++) {
    scanf("%lf%lf", &x, &y);
    ans = 0;
    tmp.x = x, tmp.y = y;
    for (p = 1, q = n; p < q;) {
      mid = ((p + q) >> 1);
      if (lef(tmp, bj[0][mid], L))
        q = mid;
      else
        p = mid + 1;
    }
    a = p - 1;
    for (p = 1, q = n; p < q;) {
      mid = ((p + q) >> 1);
      if (!lef(tmp, bj[1][mid], R))
        p = mid + 1;
      else
        q = mid;
    }
    b = p;
    printf("%.10f\n", ask(a) + ask(b) * (a != b) +
                          max((double)0, sum[b - 1] - sum[a]) * (y - sy) / y);
  }
}
