#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5;
vector<int> adj[MAXN];
int dist[MAXN];
int l[MAXN], r[MAXN];
bool vis[MAXN];
vector<int> updL[MAXN], updR[MAXN];
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
int n, k; cin >> n >> k;
int m; cin >> m;
for (int i=0; i<m; i++) {
int a, b; cin >> a >> b; a--; b--;
if (a <= b) {
// r[a...min(b, a+k-1)] = max(b)
// cout << "r: " << a << ' ' << min(b, a+k-1) << '=' << b << endl;
updR[a].push_back(b);
updR[min(b, a+k-1)].push_back(-b);
} else {
// l[max(b, a-k+1)...a] = min(a)
// cout << "l: " << max(b, a-k+1) << ' ' << a << '=' << b << endl;
updL[max(b, a-k+1)].push_back(b);
updL[a].push_back(-b);
}
}
multiset<int> pfL, pfR;
for (int i=0; i<n; i++) {
for (int x : updL[i]) {
if (x < 0) continue;
pfL.insert(x);
}
for (int x : updR[i]) {
if (x < 0) continue;
pfR.insert(x);
}
l[i] = (pfL.empty() ? i : *pfL.begin());
r[i] = (pfR.empty() ? i : *pfR.rbegin());
for (int x : updL[i]) {
if (x > 0) continue;
pfL.erase(pfL.find(-x));
}
for (int x : updR[i]) {
if (x > 0) continue;
pfR.erase(pfR.find(-x));
}
}
for (int i=0; i<n; i++) {
// cout << l[i] << ' ' << r[i] << endl;
for (int j=l[i]; j<=r[i]; j++) {
adj[i].push_back(j);
}
}
int qs; cin >> qs;
for (int q=0; q<qs; q++) {
int src, dest; cin >> src >> dest;
src--; dest--;
if (src == dest) {
cout << 0 << endl;
continue;
}
dist[src] = 1;
queue<int> visit;
for (int i=0; i<n; i++) vis[i] = false;
vis[src] = true;
bool found = false; visit.push(src);
while (!visit.empty()) {
int v = visit.front();
visit.pop();
// cout << v << endl;
if (l[v] <= dest and dest <= r[v]) {
cout << dist[v] << '\n';
found = true;
break;
}
for (int viz : adj[v]) {
if (vis[viz]) continue;
visit.push(viz);
vis[viz] = true;
dist[viz] = dist[v] + 1;
}
}
if (!found) cout << -1 << '\n';
}
return 0;
}
