#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define fs first
#define sc second
const int mxn = 1e5+10;
int N,M,K,Q;
pii range[mxn];
pii dp[mxn][20];
vector<int> lop[mxn],rop[mxn];
struct SEG{
pii segtree[mxn*4];
SEG(){
memset(segtree,0,sizeof(segtree));
}
void build(int now,int l,int r,int lvl){
if(l == r){
segtree[now] = dp[l][lvl];
return;
}
int mid = (l+r)>>1;
build(now*2+1,l,mid,lvl);
build(now*2+2,mid+1,r,lvl);
segtree[now].fs = min(segtree[now*2+1].fs,segtree[now*2+2].fs);
segtree[now].sc = max(segtree[now*2+1].sc,segtree[now*2+2].sc);
}
pii getval(int now,int l,int r,int s,int e){
if(l>=s&&e>=r)return segtree[now];
int mid = (l+r)>>1;
if(mid>=e)return getval(now*2+1,l,mid,s,e);
else if(mid<s)return getval(now*2+2,mid+1,r,s,e);
else{
auto ta = getval(now*2+1,l,mid,s,e),tb = getval(now*2+2,mid+1,r,s,e);
return make_pair(min(ta.fs,tb.fs),max(ta.sc,tb.sc));
}
}
};
SEG seg[20];
void solve(){
int s,e;
cin>>s>>e;
{
pii big = dp[s][19];
if(big.fs>e||big.sc<e){
cout<<"-1\n";
return;
}
}
pii now = {s,s};
int ans = 0;
for(int i = 19;i>=0;i--){
pii nxt = now;
nxt = seg[i].getval(0,1,N,nxt.fs,nxt.sc);
if(nxt.fs>e||nxt.sc<e){
now = nxt;
ans += 1<<i;
}
}
if(now.fs>e||now.sc<e)ans++;
cout<<ans<<'\n';
return;
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin>>N>>K>>M;
for(int i = 0;i<M;i++){
int a,b;
cin>>a>>b;
if(a<=b){
int e = min(b+1,a+K);
rop[a].push_back(b);
rop[e].push_back(-b);
}
else{
int e = max(b-1,a-K);
lop[a].push_back(b);
lop[e].push_back(-b);
}
}
for(int i = 1;i<=N;i++)range[i].fs = range[i].sc = i;
multiset<int> st;
for(int i = 1;i<=N;i++){
for(auto &j:rop[i]){
if(j>0)st.insert(j);
else st.erase(st.find(-j));
}
if(!st.empty())range[i].sc = *st.rbegin();
}
st.clear();
for(int i = N;i>=1;i--){
for(auto &j:lop[i]){
if(j>0)st.insert(j);
else st.erase(st.find(-j));
}
if(!st.empty())range[i].fs = *st.begin();
}
for(int i = 1;i<=N;i++)dp[i][0] = range[i];
seg[0].build(0,1,N,0);
for(int i = 1;i<20;i++){
for(int j = 1;j<=N;j++){
dp[j][i] = seg[i-1].getval(0,1,N,dp[j][i-1].fs,dp[j][i-1].sc);
}
seg[i].build(0,1,N,i);
}
/*
for(int i = 0;i<20;i++){
cout<<i<<":"<<endl;
for(int j = 1;j<=N;j++)cout<<dp[j][i].fs<<' ';cout<<endl;
//for(int j = 1;j<=N;j++)assert(dp[j][i].fs == seg[i].getval(0,1,N,j,j).fs);
for(int j = 1;j<=N;j++)cout<<dp[j][i].sc<<' ';cout<<endl;
for(int j = 1;j<=N;j++)cout<<seg[i].getval(0,1,N,j,j).fs<<' ';cout<<endl;
for(int j = 1;j<=N;j++)cout<<seg[i].getval(0,1,N,j,j).sc<<' ';cout<<endl;
}
*/
cin>>Q;
while(Q--)solve();
}
