#include <bits/stdc++.h>
const int C = 300001;
struct point {
  double x, y;
};
struct seg {
  point a, b;
};
struct line {
  double a, b;
};
double sy, l[C], r[C], sum[C], x, y;
int n, i, j, q;
point p, beg, end;
line k;
double bx, ex, z;
line fun(point a, point b) {
  line g;
  g.a = (a.y - b.y) / (a.x - b.x);
  g.b = a.y - (g.a * a.x);
  return g;
}
inline int binup(double tab[], double v, int l, int r) {
  int m;
  while (l <= r) {
    m = (l + r) / 2;
    if (tab[m] >= v)
      r = m - 1;
    else
      l = m + 1;
  }
  return l;
}
inline int binlow(double tab[], double v, int l, int r) {
  int m;
  while (l <= r) {
    m = (l + r) / 2;
    if (tab[m] > v)
      r = m - 1;
    else
      l = m + 1;
  }
  return r;
}
double sear(double a, double b) {
  int f, g;
  double s = 0;
  f = binup(r, a, 0, n - 1);
  g = binlow(l, b, 0, n - 1);
  if (g == f) {
    if (b > r[f] && a < l[f])
      s = s + r[f] - l[f];
    else if (b > r[f])
      s = s + r[f] - a;
    else if (a < l[f])
      s = s + b - l[f];
    else
      s = b - a;
  } else if (g > f) {
    s = s + sum[g - 1] - sum[f];
    if (b > r[g])
      s = s + r[g] - l[g];
    else
      s = s + b - l[g];
    if (a < l[f])
      s = s + r[f] - l[f];
    else
      s = s + r[f] - a;
  }
  return s / (b - a);
}
int main() {
  scanf("%lf %lf %lf", &beg.y, &beg.x, &end.x), end.y = beg.y;
  scanf("%d", &n);
  for (i = 0; i < n; i++) {
    scanf("%lf %lf", &l[i], &r[i]);
    if (i > 0)
      sum[i] = r[i] - l[i] + sum[i - 1];
    else
      sum[i] = r[i] - l[i];
  }
  scanf("%d", &q);
  while (q--) {
    scanf("%lf %lf", &p.x, &p.y);
    if (p.x == beg.x)
      bx = p.x;
    else
      k = fun(p, beg), bx = -k.b / k.a;
    if (p.x == end.x)
      ex = p.x;
    else
      k = fun(p, end), ex = -k.b / k.a;
    z = sear(bx, ex);
    printf("%.10lf\n", z * (end.x - beg.x));
  }
  return 0;
}
