#include <algorithm>
#include <climits>
#include <iostream>
#include <queue>
using namespace std;
struct Range {
int l, r;
Range(int x, int y) {
l = x;
r = y;
}
Range(int x) { l = r = x; }
Range() {
l = INT_MAX;
r = INT_MIN;
}
Range operator|(Range a) { return Range(min(l, a.l), max(r, a.r)); }
void operator|=(Range a) {
l = min(l, a.l);
r = max(r, a.r);
}
};
struct Segtree {
vector<Range> v;
int c;
void update(int x, Range y) {
x += 1 << c;
while (x) {
v[x] |= y;
x /= 2;
}
}
Range calc(int x) { return v[x + (1 << c)]; }
Range calc(int l, int r) {
l += 1 << c;
r += 1 << c;
Range x;
while (l <= r) {
x |= v[l];
x |= v[r];
l = (l + 1) / 2;
r = (r - 1) / 2;
}
return x;
}
Range calc(Range x) { return calc(x.l, x.r); }
Segtree() {}
Segtree(int n) {
c = 0;
while ((1 << c) < n) c++;
v.resize(1 << c + 1);
}
};
int N, K, M, Q, A[200000], B[200000], S[50000], T[50000];
Range R[100000];
Segtree Seg[18];
int query(int s, int t) {
int cnt = 0;
Range p;
p = Range(s);
for (int i = 17; i >= 0; i--) {
Range q = Seg[i].calc(p);
if (!(q.l <= t && t <= q.r)) {
p = q;
cnt += 1 << i;
}
}
if (cnt == (1 << 18) - 1)
return -1;
else
return cnt + 1;
}
int main() {
cin >> N >> K >> M;
for (int i = 0; i < M; i++) {
cin >> A[i] >> B[i];
A[i]--;
B[i]--;
}
cin >> Q;
for (int i = 0; i < Q; i++) {
cin >> S[i] >> T[i];
S[i]--;
T[i]--;
}
for (int i = 0; i < 18; i++) {
Seg[i] = Segtree(N);
}
for (int i = 0; i < N; i++) {
R[i] = Range(i);
}
for (int i = 0; i < M; i++) {
R[A[i]] |= Range(B[i]);
}
deque<pair<int, int>> q;
for (int i = 0; i < N; i++) {
while (!q.empty() && q.back().first < R[i].r) q.pop_back();
q.push_back({R[i].r, i + K - 1});
Seg[0].update(i, Range(q.front().first));
while (!q.empty() && q.front().second <= i) q.pop_front();
}
q.clear();
for (int i = N - 1; i >= 0; i--) {
while (!q.empty() && q.back().first > R[i].l) q.pop_back();
q.push_back({R[i].l, i - K + 1});
Seg[0].update(i, Range(q.front().first));
while (!q.empty() && q.front().second >= i) q.pop_front();
}
for (int i = 0; i < 17; i++) {
for (int j = 0; j < N; j++) {
Seg[i + 1].update(j, Seg[i].calc(Seg[i].calc(j)));
}
}
for (int i = 0; i < Q; i++) {
cout << query(S[i], T[i]) << endl;
}
}
