#include <bits/stdc++.h>
using namespace std;
//#pragma GCC optimize("O3,unroll-loops") //main
//#pragma GCC target("avx2") //cf...
//#pragma GCC target("sse4") //Quera
#define ll long long
typedef pair<int,int> pii;
typedef pair<int,pii> pip;
typedef pair<pii,int> ppi;
typedef pair<pii,pii> ppp;
#define f first
#define s second
#define lc 2*id
#define rc 2*id+1
#define all(x) x.begin(),x.end()
#define pb push_back
#define pp pop_back
#define unicorn(x) x.resize(unique(x.begin(),x.end())-x.begin())
string pr(int* vv,int l,int r){for(int i=l;i<r;i++)cout<<vv[i]<<" ";return "";}
string pr( ll* vv,int l,int r){for(int i=l;i<r;i++)cout<<vv[i]<<" ";return "";}
string pr(vector<int> vv){for(auto i:vv)cout<<i<<" ";return "";}
string pr( vector<ll> vv){for(auto i:vv)cout<<i<<" ";return "";}
string pr(pii* vv,int l,int r){for(int i=l;i<r;i++)cout<<"( "<<vv[i].f<<","<<vv[i].s<<" ) ";return "";}
string pr(vector<pii> vv){for(auto i:vv)cout<<"( "<<i.f<<","<<i.s<<" ) ";return "";}
const int L = 1e5+10,lg = 18;
const int inf = 1e9+10;
int n,m,k,q;
int hb[L];
int mx[lg][L],mn[lg][L];
struct stmx{
int st[lg][L],fn[lg][L];
stmx(){
fill(st[0]+1,st[0]+L,0);
fill(fn[0]+1,fn[0]+L,0);
}
void put(int ind,int x){
st[0][ind] = fn[0][ind] = max(st[0][ind],x);
}
void build(){
for(int j=1;j<lg;j++){
for(int i=1;i<=n;i++){
if(i+(1<<j)-1 <= n)
st[j][i] = max(st[j-1][i], st[j-1][i+(1<<(j-1))]);
if(i-(1<<j)+1 >= 1)
fn[j][i] = max(fn[j-1][i], fn[j-1][i-(1<<(j-1))]);
}
}
}
int get(int l,int r){
if(l > r)
return 0;
return max(st[hb[r-l+1]][l],fn[hb[r-l+1]][r]);
}
};
struct stmn{
int st[lg][L],fn[lg][L];
stmn(){
fill(st[0]+1,st[0]+L,L);
fill(fn[0]+1,fn[0]+L,L);
}
void put(int ind,int x){
st[0][ind] = fn[0][ind] = min(st[0][ind],x);
}
void build(){
for(int j=1;j<lg;j++){
for(int i=1;i<=n;i++){
if(i+(1<<j)-1 <= n)
st[j][i] = min(st[j-1][i], st[j-1][i+(1<<(j-1))]);
if(i-(1<<j)+1 >= 1)
fn[j][i] = min(fn[j-1][i], fn[j-1][i-(1<<(j-1))]);
}
}
}
int get(int l,int r){
if(l > r)
return L;
return min(st[hb[r-l+1]][l],fn[hb[r-l+1]][r]);
}
};
stmx frf,sx[lg];
stmn frb,sn[lg];
int main(){
//ofstream cout ("out.out");
//ifstream cin ("in.in");
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
hb[0] = -1;
for(int i=1;i<L;i++){
hb[i] = hb[i/2]+1;
}
cin>>n>>k>>m;
for(int i=1;i<=m;i++){
int l,r;
cin>>l>>r;
frf.put(l,r);
frb.put(l,r);
}
frf.build();
frb.build();
for(int i=1;i<=n;i++){
mx[0][i] = max(i,frf.get(max(1,i-k+1),i));
mn[0][i] = min(i,frb.get(i,min(i+k-1,n)));
sx[0].put(i,mx[0][i]);
sn[0].put(i,mn[0][i]);
}
sx[0].build();
sn[0].build();
for(int x=1;x<lg;x++){
for(int i=1;i<=n;i++){
mx[x][i] = sx[x-1].get(mn[x-1][i],mx[x-1][i]);
mn[x][i] = sn[x-1].get(mn[x-1][i],mx[x-1][i]);
sx[x].put(i,mx[x][i]);
sn[x].put(i,mn[x][i]);
}
sx[x].build();
sn[x].build();
}
/*
for(int i=1;i<=n;i++){
for(int j=0;j<2;j++){
cout<<"mx["<<j<<"]["<<i<<"]: "<<mn[j][i]<<" "<<mx[j][i]<<endl;
}
}
*/
cin>>q;
for(int tt=0;tt<q;tt++){
int S,F;
cin>>S>>F;
if(F < mn[lg-1][S] or F > mx[lg-1][S]){
cout<<-1<<endl;
continue;
}
int l=S, r=S;
int ans = 0;
for(int i=lg-1;i>=0;i--){
pii pre = pii(l,r);
l = sn[i].get(pre.f,pre.s);
r = sx[i].get(pre.f,pre.s);
if(F >= l and F <= r){
l = pre.f;
r = pre.s;
}
else{
ans += (1<<i);
}
}
cout<<ans+1<<endl;
}
}
