#include <bits/stdc++.h>
using namespace std;
struct Event {
int modl, modr, type;
Event() {}
Event(int _modl, int _modr, int _type) : modl(_modl), modr(_modr), type(_type) {}
};
void solve() {
int N, K;
cin >> N >> K;
int M;
cin >> M;
vector<int> A(M), B(M);
for (int i = 0; i < M; i++) {
cin >> A[i] >> B[i];
A[i]--, B[i]--;
}
vector<vector<Event>> events(N);
for (int i = 0; i < M; i++) {
if (A[i] < B[i]) {
events[A[i]].emplace_back(N, B[i], 1);
events[min(A[i] + K - 1, B[i])].emplace_back(N, B[i], -1);
} else {
events[max(A[i] - K + 1, B[i])].emplace_back(B[i], -1, 1);
events[A[i]].emplace_back(B[i], -1, -1);
}
}
vector<int> L(N), R(N);
multiset<int> sl, sr;
for (int i = 0; i < N; i++) {
L[i] = i, R[i] = i;
for (auto [modl, modr, type] : events[i]) {
if (type == 1) {
sl.insert(modl);
sr.insert(modr);
}
}
if (!sl.empty()) {
L[i] = min(L[i], *sl.begin());
R[i] = max(R[i], *sr.rbegin());
}
for (auto [modl, modr, type] : events[i]) {
if (type == -1) {
sl.erase(sl.find(modl));
sr.erase(sr.find(modr));
}
}
}
int Q;
cin >> Q;
while (Q--) {
int S, T;
cin >> S >> T;
S--, T--;
queue<int> q;
set<int> unvisited;
for (int i = 0; i < N; i++) {
if (i != S) {
unvisited.insert(i);
}
}
vector<int> dist(N, N);
dist[S] = 0;
q.push(S);
while (!q.empty()) {
int u = q.front();
q.pop();
auto it = unvisited.lower_bound(L[u]);
while (it != unvisited.end() && *it <= R[u]) {
dist[*it] = dist[u] + 1;
q.push(*it);
it = next(it);
unvisited.erase(prev(it));
}
}
cout << (dist[T] == N ? -1 : dist[T]) << "\n";
}
}
int main() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
