#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1<<17;
const int MAXP = 19;
int droite[MAXN];
int gauche[MAXN];
struct inter
{
int deb,fin;
bool operator == (const inter & autre) const
{
return deb == autre.deb && fin == autre.fin;
}
};
inter vide = {-1 , -1};
struct prQ
{
int val , pos;
};
inter union_inter(inter a , inter b)
{
if (a == vide) return b;
if (b == vide) return a;
return {min(a.deb , b.deb) , max(a.fin , b.fin)};
}
inter intervalles[MAXN * 2][MAXP];
void init()
{
for (int i = 0 ; i < MAXN * 2 ; i++)
{
for (int j = 0 ; j < MAXP ; j++)
{
intervalles[i][j] = vide;
}
}
}
void remplir_etage(int et)
{
for (int i = MAXN- 1 ; i > 0 ; i--)
{
intervalles[i][et] = union_inter(intervalles[i * 2][et] , intervalles[i * 2 + 1][et]);
}
}
inter maxi(int deb , int fin , int et)
{
deb += MAXN;
fin += MAXN;
inter rep = vide;
while (deb <= fin)
{
if (deb % 2 == 1)
{
rep = union_inter(rep , intervalles[deb][et]);
deb++;
}
if (fin % 2 == 0)
{
rep = union_inter(rep , intervalles[fin][et]);
fin--;
}
deb/=2;
fin/=2;
}
return rep;
}
bool contient (inter a , int b)
{
return a.deb <= b && a.fin >= b;
}
int main()
{
init();
int N , K;
cin >> N >> K;
int M;
cin >> M;
for (int i = 0 ; i < MAXN ; i++)
{
droite[i] = -1;
gauche[i] = -1;
}
for (int i = 0 ; i < M ; i++)
{
int a,b;
cin >> a >> b;
a--; b--;
if (a < b)
{
droite[a] = max(droite[a] , b);
}
else
{
if (gauche[a] == -1) gauche[a] = b;
else gauche[a] = min(gauche[a] , b);
}
}
deque<prQ> Q;
for (int i = 0 ; i < N ; i++)
{
if (droite[i] != -1)
{
while (!Q.empty() && Q.front().val <= droite[i])
Q.pop_front();
Q.push_front({droite[i] , i});
}
while (!Q.empty() && Q.back().pos + K <= i)
Q.pop_back();
if (Q.empty())
intervalles[i + MAXN][0].fin = i;
else
intervalles[i + MAXN][0].fin = max(i , Q.back().val);
}
Q.clear();
for (int i = N - 1 ; i >= 0 ; i--)
{
if (gauche[i] != -1)
{
while (!Q.empty() && Q.front().val >= gauche[i])
Q.pop_front();
Q.push_front({gauche[i] , i});
}
while (!Q.empty() && Q.back().pos - K >= i)
Q.pop_back();
if (Q.empty())
intervalles[i + MAXN][0].deb = i;
else
{
// cout<<"A"<<i<<" "<<Q.back().pos<<endl;
intervalles[i + MAXN][0].deb = min(i , Q.back().val);
}
}
/*for (int i = 0 ; i < N ; i++)
{
cout<<intervalles[i + MAXN][0].deb<<" "<<intervalles[i + MAXN][0].fin<<endl;
}*/
remplir_etage(0);
for (int iP = 1 ; iP < MAXP ; iP++)
{
for (int i = 0 ; i < N ; i++)
{
intervalles[i + MAXN][iP] = maxi(intervalles[i + MAXN][iP - 1].deb , intervalles[i + MAXN][iP - 1].fin , iP - 1);
}
remplir_etage(iP);
}
int nbQ;
cin >> nbQ;
for (int i = 0 ; i < nbQ ; i++)
{
int s,t;
cin >> s >> t;
s--; t--;
inter tout = maxi(s , s , MAXP - 1);
if (!contient(tout , t)) {cout<<-1<<endl; continue;}
if (s == t) {cout<<0<<endl; continue;}
int rep = 0;
inter actu = {s , s};
for (int iP = MAXP - 1 ; iP >= 0 ; iP--)
{
inter in = maxi(actu.deb , actu.fin , iP);
if (!contient(in , t))
{
actu = in;
rep += 1<<iP;
}
}
cout<<rep + 1<<endl;
}
}
