#include <bits/stdc++.h>
using namespace std;
const int N = 200'000 + 10;
int n, k;
int m, q;
struct Train {
int st, ed;
friend istream& operator >> (istream& is, Train& rhs) {
return is >> rhs.st >> rhs.ed;
}
} train[N];
struct IT {
using pii = pair<int, int>;
pii f[N << 2];
pii merge(const pii& lt, const pii& rt) {
return {min(lt.first, rt.first), max(lt.second, rt.second)};
}
void build(int u, int l, int r) {
if (l == r) {
f[u] = {l, l};
return;
}
int mid = (l + r) >> 1;
build(u << 1, l, mid);
build(u << 1 | 1, mid + 1, r);
f[u] = merge(f[u << 1], f[u << 1 | 1]);
}
void update(int u, int l, int r, int pos, pii val) {
if (l == r) {
f[u] = merge(f[u], val);
return;
}
int mid = (l + r) >> 1;
if (pos <= mid) update(u << 1, l, mid, pos, val);
else update(u << 1 | 1, mid + 1, r, pos, val);
f[u] = merge(f[u << 1], f[u << 1 | 1]);
}
pii query(int u, int l, int r, int ql, int qr) {
if (ql <= l && r <= qr) return f[u];
int mid = (l + r) >> 1;
pii res = {n + 1, 0};
if (ql <= mid) res = merge(res, query(u << 1, l, mid, ql, qr));
if (qr > mid) res = merge(res, query(u << 1 | 1, mid + 1, r, ql, qr));
return res;
}
} T[18];
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> k;
cin >> m;
for (int i = 1; i <= m; ++i) cin >> train[i];
{ // cal f[][0]
vector<tuple<int, int, int>> vt;
for (int i = 1; i <= m; ++i) {
const auto& [st, ed] = train[i];
if (st < ed) {
int p = min(ed - 1, st + k - 1);
vt.emplace_back(ed, st, p);
} else {
int p = max(ed + 1, st - k + 1);
vt.emplace_back(ed, p, st);
}
}
for (int j = 0; j < 18; ++j) T[j].build(1, 1, n);
for (int turn = 0; turn < 2; ++turn) {
if (!turn) sort(vt.begin(), vt.end());
else sort(vt.begin(), vt.end(), greater<>());
set<int> s;
for (int i = 1; i <= n; ++i) s.insert(i);
for (const auto& [value, l, r] : vt) {
auto it = s.lower_bound(l);
while (it != s.end() && *it <= r) {
int i = *it;
T[0].update(1, 1, n, i, {value, value});
it = s.erase(it);
}
}
}
}
{ // cal f[i] for sparse table
for (int j = 1; j < 18; ++j) {
for (int i = 1; i <= n; ++i) {
auto [l, r] = T[j - 1].query(1, 1, n, i, i);
T[j].update(1, 1, n, i, T[j - 1].query(1, 1, n, l, r));
}
}
}
cin >> q;
while (q--) {
int st, ed; cin >> st >> ed;
if (st == ed) {
cout << 0 << "\n";
continue;
}
int answer = 0;
int l = st, r = st;
for (int j = 17; j >= 0; --j) {
auto [lt, rt] = T[j].query(1, 1, n, l, r);
if (lt <= ed && ed <= rt) continue;
l = lt;
r = rt;
answer |= (1 << j);
}
{ // check if can reach ed
auto [lt, rt] = T[0].query(1, 1, n, l, r);
if (lt <= ed && ed <= rt) answer += 1;
else answer = -1;
}
cout << answer << '\n';
}
}
