#include<bits/stdc++.h>
using namespace std;
int n, k, m, q;
int a, b;
vector<int> l[100005], r[100005];
priority_queue< pair<int,int> > pq;
int L[100005][20][20], R[100005][20][20];
int LOG2[100005];
pair<int,int> findRange(int l, int r, int j) {
pair<int,int> rv;
int LOG = LOG2[r-l+1];
rv.first = min(L[l][j][LOG], L[r-(1<<LOG)+1][j][LOG]);
rv.second = max(R[l][j][LOG], R[r-(1<<LOG)+1][j][LOG]);
return rv;
}
int main() {
ios::sync_with_stdio(false);
for(int i=2; i<=1e5; i++) LOG2[i] = LOG2[i/2] + 1;
cin >> n >> k >> m;
for(int i=0; i<m; i++) {
cin >> a >> b;
if(a < b) {
l[a].push_back(b);
} else {
r[a].push_back(b);
}
}
for(int i=1; i<=n; i++) {
for(int j:l[i]) pq.push({j, i});
while(!pq.empty() && pq.top().second<i-k+1) pq.pop();
R[i][0][0] = i;
if(!pq.empty()) {
R[i][0][0] = max(R[i][0][0], pq.top().first);
}
}
while(!pq.empty()) pq.pop();
for(int i=n; i>=1; i--) {
for(int j:r[i]) pq.push({-j, i});
while(!pq.empty() && pq.top().second>i+k-1) pq.pop();
L[i][0][0] = i;
if(!pq.empty()) {
L[i][0][0] = min(L[i][0][0], -pq.top().first);
}
}
for(int j=0; j<=19; j++) {
if(j>0)
for(int i=1; i<=n; i++) {
int LL = L[i][j-1][0];
int RR = R[i][j-1][0];
int LOG = LOG2[RR-LL+1];
L[i][j][0] = min(L[LL][j-1][LOG], L[RR-(1<<LOG)+1][j-1][LOG]);
R[i][j][0] = max(R[LL][j-1][LOG], R[RR-(1<<LOG)+1][j-1][LOG]);
}
for(int k=1; k<=19; k++) {
for(int i=1; i<=n; i++) {
if(i+(1<<k)-1 > n) break;
L[i][j][k] = min(L[i][j][k-1], L[i+(1<<(k-1))][j][k-1]);
R[i][j][k] = max(R[i][j][k-1], R[i+(1<<(k-1))][j][k-1]);
}
}
}
cin >> q;
while(q--) {
cin >> a >> b;
int ans = 0;
if(L[a][19][0] > b || R[a][19][0] < b) {
cout << "-1\n";
} else {
int ans = 0, lo = a, hi = a;
for(int j=19; j>=0; j--) {
pair<int,int> range = findRange(lo, hi, j);
if(range.first > b || range.second < b) {
ans += (1<<j);
lo = range.first;
hi = range.second;
}
}
cout << ans+1 << "\n";
}
}
}
