#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = double;
const int LOG = 21;
const int MAXM = 1e5;
int lift[MAXM + 1][LOG + 1];
struct RMQ {
vector<int> tree;
int n;
void init(int n) {
this->n = n;
tree = vector<int>(4 * n, -1);
}
void update(int i, int l, int r, int qp, int val) {
if (l == r) {
tree[i] = max(tree[i], val);
return;
}
int m = (l + r) / 2;
if (qp <= m) update(i * 2, l, m, qp, val);
else update(i * 2 + 1, m + 1, r, qp, val);
tree[i] = max(tree[i * 2], tree[i * 2 + 1]);
}
void update(int qp, int val) {
update(1, 1, n, qp, val);
}
int query(int i, int l, int r, int ql, int qr) {
if (l > qr || r < ql) return -1;
if (ql <= l && r <= qr) return tree[i];
int m = (l + r) / 2;
return max(query(i * 2, l, m, ql, qr), query(i * 2 + 1, m + 1, r, ql, qr));
}
int query(int ql, int qr) {
return query(1, 1, n, ql, qr);
}
};
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int n, k, m;
cin >> n >> k >> m;
for (int i = 0; i <= n; ++i) {
for (int j = 0; j < LOG; ++j) {
lift[i][j] = -1;
}
}
vector<vector<array<int, 2>>> events(n + 1);
for (int i = 0; i < m; ++i) {
int a, b;
cin >> a >> b;
assert(a < b);
int till = min(b, a + k);
events[a].push_back({b, till});
events[till].push_back({-b, till});
}
multiset<pair<int, int>> mt;
for (int j = 1; j <= n; ++j) {
for (auto& u : events[j]) {
if (u[0] < 0) {
mt.erase(mt.find({-u[0], u[1]}));
} else {
mt.insert({u[0], u[1]});
}
}
if (mt.size() > 0) {
auto it = prev(mt.end());
lift[j][0] = it->first;
}
}
//~ for (int i = 1; i <= n; ++i) {
//~ cerr << lift[i][0] << " ";
//~ }
//~ cerr << "\n";
vector<RMQ> lifts(LOG + 1);
for (int i = 0; i <= LOG; ++i) {
lifts[i].init(n);
for (int j = 1; j <= n; ++j) {
lifts[i].update(j, lift[j][i]);
}
for (int j = 1; j <= n; ++j) {
lift[j][i + 1] = lifts[i].query(j, lift[j][i]);
}
}
//~ for (int i = 1; i <= n; ++i) {
//~ cerr << lifts[1].query(i, i) << " ";
//~ }
//~ cerr << "\n";
//~ for (int i = 1; i <= n; ++i) {
//~ cerr << lifts[2].query(i, i) << " ";
//~ }
//~ cerr << "\n";
int q;
cin >> q;
while (q--) {
int a, b;
cin >> a >> b;
assert(a < b);
int res = 0;
int nxt = a;
for (int i = LOG; i >= 0; --i) {
int NEXT = lifts[i].query(a, nxt);
//~ cerr << a << " -> " << nxt << "\n";
if (NEXT > nxt && NEXT < b) {
nxt = NEXT;
res += (1 << i);
}
}
res += 1;
a = lifts[0].query(a, nxt);
//~ cerr << a << " " << b << " = ";
if (a < b) {
cout << "-1\n";
continue;
}
cout << res << "\n";
}
}
