#include <iostream>
#include <vector>
#include <map>
#include <stack>
#define ll long long
using namespace std;
const int N = 520005, K = 20, inf = 1e9;
int n, k, m, q, min_l[K][N], max_r[K][N], s = 1, treer[N], treel[N];
void updateR(int l, int r, int v) {
l += s;
r += s;
treer[l] = max(treer[l], v);
treer[r] = max(treer[r], v);
while (l + 1 < r) {
if (!(l & 1)) {
treer[l + 1] = max(treer[l + 1], v);
}
if (r & 1) {
treer[r - 1] = max(treer[r - 1], v);
}
r >>= 1;
l >>= 1;
}
}
void updateL(int l, int r, int v) {
l += s;
r += s;
treel[l] = min(treel[l], v);
treel[r] = min(treel[r], v);
while (l + 1 < r) {
if (!(l & 1)) {
treel[l + 1] = min(treel[l + 1], v);
}
if (r & 1) {
treel[r - 1] = min(treel[r - 1], v);
}
r >>= 1;
l >>= 1;
}
}
int findR(int l, int r, int bit) {
l += s;
r += s;
int maxi = max(max_r[bit][l], max_r[bit][r]);
while (l + 1 < r) {
if (!(l & 1)) {
maxi = max(maxi, max_r[bit][l + 1]);
}
if (r & 1) {
maxi = max(maxi, max_r[bit][r - 1]);
}
r >>= 1;
l >>= 1;
}
return maxi;
}
int findL(int l, int r, int bit) {
l += s;
r += s;
int mini = min(min_l[bit][l], min_l[bit][r]);
while (l + 1 < r) {
if (!(l & 1)) {
mini = min(mini, min_l[bit][l + 1]);
}
if (r & 1) {
mini = min(mini, min_l[bit][r - 1]);
}
r >>= 1;
l >>= 1;
}
return mini;
}
int fl(int i) {
i += s;
int mini = inf;
while (i > 0) {
mini = min(mini, treel[i]);
i >>= 1;
}
return mini;
}
int fr(int i) {
i += s;
int maxi = 0;
while (i > 0) {
maxi = max(maxi, treer[i]);
i >>= 1;
}
return maxi;
}
int main()
{
cin.tie(0);
cout.tie(0);
ios_base::sync_with_stdio(0);
cin >> n >> k >> m;
while (s <= n)
s <<= 1;
for (int i = 0; i <= 2 * s; i++) {
treel[i] = inf;
treer[i] = 0;
}
for (int i = 0; i < m; i++) {
int a, b;
cin >> a >> b;
if (a < b) {
updateR(a, min(a + k - 1, b), b);
}
else
{
updateL(max(b, a - k + 1), a, b);
}
}
for (int i = 0; i <= n; i++) {
min_l[0][i + s] = min(i, fl(i));
max_r[0][i + s] = max(i, fr(i));
}
for (int i = s - 1; i > 0; i--) {
min_l[0][i] = min(min_l[0][2 * i], min_l[0][2 * i + 1]);
max_r[0][i] = max(max_r[0][2 * i], max_r[0][2 * i + 1]);
}
for (int j = 1; j < K; j++) {
for (int i = 1; i < 2 * s; i++) {
min_l[j][i] = findL(min_l[j - 1][i], max_r[j - 1][i], j - 1);
max_r[j][i] = findR(min_l[j - 1][i], max_r[j - 1][i], j - 1);
}
}
cin >> q;
for (; q--;) {
int a, b;
cin >> a >> b;
int l = a, r = a, res = 0;
bool ok = 0;
for (int i = K - 1; i >= 0; i--) {
int new_l = findL(l, r, i), new_r = findR(l, r, i);
if (new_l <= b && new_r >= b)
ok = 1;
else {
res += (1 << i);
l = new_l;
r = new_r;
}
}
if (ok)
cout << res + 1 << '\n';
else
cout << -1 << '\n';
}
}
