#include <bits/stdc++.h>
#define pb push_back
#define fst first
#define snd second
#define fore(i,a,b) for(int i=a,pao=b;i<pao;++i)
#define SZ(x) ((int)x.size())
#define ALL(x) x.begin(),x.end()
#define me(a,v) memset((a),(v),sizeof(a))
#define FIN ios::sync_with_stdio(0);cin.tie(0);cout.tie(0)
using namespace std;
typedef long long ll;
const int MAXM=2e5+5,MAXN=1e5+5,INF=1e9;
int A[MAXM],B[MAXM],L[MAXN],R[MAXN],sig[MAXN];
void chmin(int &a,int b){
if(a>b)a=b;
}
void chmax(int &a,int b){
if(a<b)a=b;
}
int main(){FIN;
int n,k;cin>>n>>k;
int m;cin>>m;
fill(L,L+n,INF);
fill(R,R+n,-INF);
vector<vector<int>>add(n),rem(n);
vector<vector<int>>add2(n),rem2(n);
fore(i,0,m){
cin>>A[i]>>B[i];
A[i]--;B[i]--;
if(A[i]<B[i]){
add[A[i]].pb(B[i]);
rem[min(A[i]+k,B[i]+1)].pb(B[i]);
}else{
add2[A[i]].pb(B[i]);
rem2[max(A[i]-k,B[i]-1)].pb(B[i]);
}
}
multiset<int>s;
fore(i,0,n){
if(!s.empty())for(auto x:rem[i])s.erase(s.find(x));
for(auto x:add[i])s.insert(x);
if(!s.empty())chmax(R[i],*s.rbegin());
}
s.clear();
for(int i=n-1;i>=0;i--){
if(!s.empty())for(auto x:rem2[i])s.erase(s.find(x));
for(auto x:add2[i])s.insert(x);
if(!s.empty())chmin(L[i],*s.begin());
}
me(sig,-1);
int Q;cin>>Q;
while(Q--){
int s,t;cin>>s>>t;s--;t--;
queue<pair<int,int>>q;q.push({s,s});
int steps=0;
while(!q.empty()){
auto prev=q.front();q.pop();
if(prev.fst<=t&&t<=prev.snd){
cout<<steps<<endl;
break;
}
steps++;
pair<int,int>next=prev;
for(int i=prev.fst;i<=prev.snd;i++){
if(sig[i]!=-1)i=sig[i];
chmin(next.fst,L[i]);
chmax(next.snd,R[i]);
}
sig[prev.fst]=prev.snd+1;
if(next==prev){
cout<<-1<<endl;
break;
}
q.push(next);
}
}
}
