#include <bits/stdc++.h>
using namespace std;
const int maxn = 100010;
int n, K, m, q, mx[maxn], mn[maxn];
int f[18][maxn], g[18][maxn], st1[18][18][maxn], st2[18][18][maxn];
int main() {
scanf("%d %d %d", &n, &K, &m);
iota(mx + 1, mx + n + 1, 1);
iota(mn + 1, mn + n + 1, 1);
for (int i = 1, a, b; i <= m; i++) {
scanf("%d %d", &a, &b);
if (a < b) mx[a] = max(mx[a], b);
else mn[a] = min(mn[a], b);
}
deque<int> Q;
for (int i = n; i; i--) {
while (!Q.empty() && mn[Q.back()] > mn[i]) Q.pop_back();
Q.push_back(i);
while (Q.front() >= i + K) Q.pop_front();
f[0][i] = mn[Q.front()];
}
Q.clear();
for (int i = 1; i <= n; i++) {
while (!Q.empty() && mx[Q.back()] < mx[i]) Q.pop_back();
Q.push_back(i);
while (Q.front() <= i - K) Q.pop_front();
g[0][i] = mx[Q.front()];
}
auto qmin = [&](int st[18][maxn], int l, int r) {
int k = __lg(r - l + 1);
return min(st[k][l], st[k][r - (1 << k) + 1]);
};
auto qmax = [&](int st[18][maxn], int l, int r) {
int k = __lg(r - l + 1);
return max(st[k][l], st[k][r - (1 << k) + 1]);
};
for (int k = 0; k < 18; k++) {
if (k) {
for (int i = 1; i <= n; i++) {
f[k][i] = qmin(st1[k - 1], f[k - 1][i], g[k - 1][i]);
g[k][i] = qmax(st2[k - 1], f[k - 1][i], g[k - 1][i]);
}
}
for (int i = 1; i <= n; i++) {
st1[k][0][i] = f[k][i], st2[k][0][i] = g[k][i];
}
for (int i = 1; i < 18; i++) {
for (int j = 1; j + (1 << i) - 1 <= n; j++) {
st1[k][i][j] = min(st1[k][i - 1][j], st1[k][i - 1][j + (1 << (i - 1))]);
st2[k][i][j] = max(st2[k][i - 1][j], st2[k][i - 1][j + (1 << (i - 1))]);
}
}
}
scanf("%d", &q);
while (q--) {
int s, t;
scanf("%d %d", &s, &t);
int l = s, r = s, ans = 0;
for (int i = 17; ~i; i--) {
int _l = qmin(st1[i], l, r), _r = qmax(st2[i], l, r);
if (_r < t || _l > t) l = _l, r = _r, ans |= 1 << i;
}
printf("%d\n", ans > n ? -1 : ans + 1);
}
return 0;
}
