#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize ("O3,unroll-loops")
#pragma GCC target ("avx2,bmi,bmi2,lzcnt,popcnt")
const int N = 1e5 + 7;
const int M = 20;
const int inf = 1e9 + 7;
struct SEGT{//range update , range query
vector < int > tree;
int sz;
SEGT(){
sz = N;
tree.assign(4 * sz , -inf);
}
inline int _query(int ind , int l , int r , int ql , int qr){
if(l >= ql and r <= qr)return tree[ind];
else if(l > qr or r < ql)return -inf;
int mid = (l+r)/2;
return max(_query(ind*2,l,mid,ql,qr) , _query(ind*2+1,mid+1,r,ql,qr));
}
inline int query(int l , int r){return _query(1,1,sz,l,r);}
inline void _update(int ind , int l , int r , int qp , int qv){
if(l == r){
tree[ind] = max(tree[ind] , qv);
return;
}
int mid = (l+r)/2;
if(mid >= qp)_update(ind*2,l,mid,qp,qv);
else _update(ind*2+1,mid+1,r,qp,qv);
tree[ind] = max(tree[ind*2] , tree[ind*2+1]);
}
inline void update(int p ,int v){_update(1,1,sz,p,v);}
};
SEGT leftmost[M],rightmost[M];
void solve(){
int n,k,m;cin >> n >> k >> m;
int a[m],b[m];
multiset < int > sol[N],sag[N],soldel[N],sagdel[N];
for(int i = 1;i<N;i++){
leftmost[0].update(i,-i);
rightmost[0].update(i,i);
}
for(int i = 0;i<m;i++){
cin >> a[i] >> b[i];
if(a[i] < b[i]){
sol[a[i]].insert(b[i]);
soldel[a[i]+k-1].insert(b[i]);
}
else{
sag[a[i]].insert(b[i]);
sagdel[a[i]-k+1].insert(b[i]);
}
}
multiset < int > cur;
for(int i = 1;i<N;i++){
for(auto itr : sol[i])cur.insert(itr);
if(cur.size())rightmost[0].update(i,*--cur.end());
for(auto itr : soldel[i])cur.extract(itr);
}
cur.clear();
for(int i = N-1;i>=1;i--){
for(auto itr : sag[i])cur.insert(itr);
if(cur.size())leftmost[0].update(i,-*cur.begin());
for(auto itr : sagdel[i])cur.extract(itr);
}
//cout << "leftmost : ";for(int i = 1;i<=n;i++)cout << leftmost[0].query(i,i) << " ";cout << endl;
//cout << "rightmost : ";for(int i = 1;i<=n;i++)cout << rightmost[0].query(i,i) << " ";cout << endl;
for(int i = 1;i<M;i++){
for(int j = 1;j<=n;j++){
int lp = -leftmost[i-1].query(j , j);
int rp = rightmost[i-1].query(j , j);
leftmost[i].update(j , leftmost[i-1].query(lp , rp));
rightmost[i].update(j , rightmost[i-1].query(lp , rp));
}
}
int q;cin >> q;
while(q--){
int s,t,ans=0;cin >> s >> t;
if(s == t){
cout << 0 << endl;
return;
}
pair < int , int > cur = {s,s};
bool bl = 1;
for(int i = M-1;i>=0;i--){
pair < int , int > ncur = {-leftmost[i].query(cur.first,cur.second) , rightmost[i].query(cur.first,cur.second)};
if(ncur.second < t or ncur.first > t){//al
cur = ncur;
ans += 1 << i;
}
else bl = 0;
}
cout << (bl?-1:ans+1) << '\n';
}
}
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);
int testcase = 1;//cin >> testcase;
while(testcase--)solve();
}
