/*
author : abushbandit
contest : ---
*/
#include "bits/stdc++.h"
using namespace std;
#define int long long
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define pb push_back
#define ff first
#define ss second
const int INF = 1e18;
const int p = 37,m = 1e9 + 11;
const int p1 = 101,m1 = 1e9 + 7;
const int N = 1e5 + 1;
pair<int,int> t[N * 4];
int lazy[N * 4];
pair<int,int> getmax(pair<int,int> a,pair<int,int> b){
if(a.ff > b.ff){
return a;
} else if(a.ff < b.ff){
return b;
} else{
if(a.ss < b.ss){
return b;
} else{
return a;
}
}
}
void push(int v,int tl,int tr){
if(!lazy[v]) return;
if(tl != tr){
lazy[v * 2] = max(lazy[v],lazy[v * 2]);
lazy[v * 2 + 1] = max(lazy[v],lazy[v * 2 + 1]);
}
t[v] = getmax(t[v],{lazy[v],tr});
lazy[v] = 0;
}
void update(int l,int r,int val,int v,int tl,int tr){
push(v,tl,tr);
if(l <= tl && tr <= r){
lazy[v] = val;
push(v,tl,tr);
return;
}
if(l > tr || tl > r){
return;
}
int tm = (tl + tr) >> 1;
update(l,r,val,v * 2,tl,tm);
update(l,r,val,v * 2 + 1,tm + 1,tr);
t[v] = getmax(t[v * 2],t[v * 2 + 1]);
}
pair<int,int> get(int l,int r,int v,int tl,int tr){
push(v,tl,tr);
if(l <= tl && tr <= r){
return t[v];
}
if(l > tr || tl > r){
return {0,0};
}
int tm = (tl + tr) >> 1;
return getmax(get(l,r,v * 2,tl,tm),get(l,r,v * 2 + 1,tm + 1,tr));
}
pair<int,int> getmin(pair<int,int> a,pair<int,int> b){
if(a.ff < b.ff){
return a;
} else if(a.ff > b.ff){
return b;
} else{
if(a.ss > b.ss){
return b;
} else{
return a;
}
}
}
pair<int,int> tdown[N * 4];
int lazy1[N * 4];
void push1(int v,int tl,int tr){
if(lazy1[v] == INF) return;
if(tl != tr){
lazy1[v * 2] = min(lazy1[v],lazy1[v * 2]);
lazy1[v * 2 + 1] = min(lazy1[v],lazy1[v * 2 + 1]);
}
tdown[v] = getmin(tdown[v],{lazy1[v],tl});
lazy1[v] = INF;
}
void update1(int l,int r,int val,int v,int tl,int tr){
push1(v,tl,tr);
if(l <= tl && tr <= r){
lazy1[v] = val;
push1(v,tl,tr);
return;
}
if(l > tr || tl > r){
return;
}
int tm = (tl + tr) >> 1;
update1(l,r,val,v * 2,tl,tm);
update1(l,r,val,v * 2 + 1,tm + 1,tr);
tdown[v] = getmin(tdown[v * 2],tdown[v * 2 + 1]);
}
pair<int,int> get1(int l,int r,int v,int tl,int tr){
push1(v,tl,tr);
if(l <= tl && tr <= r){
return tdown[v];
}
if(l > tr || tl > r){
return {INF,INF};
}
int tm = (tl + tr) >> 1;
return getmin(get1(l,r,v * 2,tl,tm),get1(l,r,v * 2 + 1,tm + 1,tr));
}
void solve() {
for(int i = 0;i < N * 4;i++){
tdown[i] = {INF,INF};
lazy1[i] = INF;
t[i] = {0,0};
}
int n,k;
cin >> n >> k;
int m;
cin >> m;
vector<int> up(n + 1,-INF);
vector<int> down(n + 1,INF);
for(int i = 0;i < m;i++){
int a,b;
cin >> a >> b;
if(a < b){
up[a] = max(up[a],b);
} else{
down[a] = min(down[a],b);
}
}
for(int j = 1;j <= n;j++){
if(up[j] != -INF){
update(j,min(j + k - 1,up[j] - 1),up[j],1,1,n);
}
if(down[j] != INF){
update1(max(j - k + 1,down[j] + 1),j,down[j],1,1,n);
}
}
int mx[n + 1],mn[n + 1];
for(int i = 1;i <= n;i++){
mx[i] = get(i,i,1,1,n).ff;
mn[i] = get1(i,i,1,1,n).ff;
}
int q;
cin >> q;
for(int i = 0;i < q;i++){
int a,b;
cin >> a >> b;
queue<int> q;
q.push(a);
vector<int> dis(n + 1,INF);
int ans = -1;
dis[a] = 0;
while(!q.empty()){
int top = q.front();
q.pop();
int to1 = mx[top];
int to2 = mn[top];
if(a < b && to1 >= b){
ans = dis[top] + 1;
break;
}
if(a > b && to2 <= b){
ans = dis[top] + 1;
break;
}
if(to1 != 0)
to1 = get(top,to1,1,1,n).ss;
if(to2 != INF)
to2 = get1(to2,top,1,1,n).ss;
if(to1 != 0 && dis[to1] > dis[top] + 1){
dis[to1] = dis[top] + 1;
q.push(to1);
}
if(to2 != INF && dis[to2] > dis[top] + 1){
dis[to2] = dis[top] + 1;
q.push(to2);
}
}
cout << ans << "\n";
}
}
signed main() {
ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
int t = 1;
//~ cin >> t;
while(t--){
solve();
}
}
