#include<bits/stdc++.h>
#define fi first
#define se second
using namespace std;
const int N=1e5;
const int L=20;
const int P=(1<<17);
struct Seg
{
int l,r;
};
Seg operator+(Seg a,Seg b)
{
return {min(a.l,b.l),max(a.r,b.r)};
}
vector<int> ev[N+10];
multiset<int> ms;
Seg jmp[N+10][L+2];
int pot;
Seg tr[L+2][2*P+10];
void buildtr(int n,int l)
{
for(int i=1;i<=n;i++)
tr[l][pot+i-1]=jmp[i][l];
for(int i=pot-1;i>0;i--)
tr[l][i]=tr[l][2*i]+tr[l][2*i+1];
return;
}
Seg read(int it,int l,int r)
{
Seg ans={N+1,0};
for(l+=pot-1,r+=pot-1;l<=r;l/=2,r/=2)
{
if(l%2==1)
ans=ans+tr[it][l++];
if(r%2==0)
ans=ans+tr[it][r--];
}
return ans;
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
int n,k,m,q;
cin>>n>>k>>m;
for(int i=1;i<=m;i++)
{
int a,b;
cin>>a>>b;
if(a<b)
{
ev[a].push_back(b);
ev[min(a+k,b+1)].push_back(-b);
}
else
{
ev[max(a-k+1,b)].push_back(b);
ev[a+1].push_back(-b);
}
}
for(int i=1;i<=n;i++)
{
for(auto v:ev[i])
{
if(v>0)
ms.insert(v);
else
ms.erase(ms.find(-v));
}
if(ms.empty())
jmp[i][0]={i,i};
else
jmp[i][0]={min(i,*ms.begin()),max(i,*prev(ms.end()))};
//cerr<<i<<": "<<jmp[i][0].l<<" "<<jmp[i][0].r<<"\n";
}
for(pot=1;pot<n;pot*=2);
buildtr(n,0);
for(int l=1;l<=L;l++)
{
for(int i=1;i<=n;i++)
jmp[i][l]=read(l-1,jmp[i][l-1].l,jmp[i][l-1].r);
buildtr(n,l);
}
cin>>q;
while(q--)
{
int a,b;
cin>>a>>b;
if(a==b)
{
cout<<"0\n";
return 0;
}
Seg s={a,a};
if(b<jmp[a][L].l || jmp[a][L].r<b)
{
cout<<"-1\n";
continue;
}
int ans=0;
for(int l=L;l>=0;l--)
{
Seg tmp=read(l,s.l,s.r);
if(b<tmp.l || tmp.r<b)
{
s=tmp;
ans+=(1<<l);
}
}
cout<<ans+1<<"\n";
}
return 0;
}
