using namespace std;
#include <iostream>
#include <algorithm>
#include <utility>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
typedef long long LL;
typedef pair<int,int> pii;
#define pb push_back
#define mkp make_pair
#define F first
#define S second
#define iter(x) x.begin(),x.end()
#define REP(n) for (int __=n;__--;)
#define REP0(i,n) for (int i=0;i<n;++i)
#define REP1(i,n) for (int i=1;i<=n;++i)
const int maxn = 1e5+10, mod = 0;
const LL inf = 0;
int mx[maxn], mn[maxn];
struct segmenttree{
int val[maxn*4], type;
int pull(int l, int r){
return type == 1 ? max(l, r) : min(l, r);
}
void maketree(int cur, int LB, int RB){
if (LB == RB){
if (type == 1) val[cur] = mx[LB];
else val[cur] = mn[LB];
}
else{
int m = (LB + RB) / 2;
maketree(cur*2, LB, m);
maketree(cur*2+1, m+1, RB);
val[cur] = pull(val[cur*2], val[cur*2+1]);
}
}
void init(int n, int _type){
type = _type;
maketree(1, 1 ,n);
}
int query(int l, int r, int cur, int LB, int RB){
if (l == LB and r == RB) return val[cur];
int m = (LB + RB) / 2;
if (r <= m) return query(l, r, cur*2, LB, m);
else if (l > m) return query(l, r, cur*2+1, m+1, RB);
else return pull(query(l, m, cur*2, LB, m), query(m+1, r, cur*2+1, m+1, RB));
}
}seg[2];
void solve(){
int n, k, m, q;
cin >> n >> k >> m;
REP1(i, n) mn[i] = mx[i] = i;
REP(m){
int a, b;
cin >> a >> b;
mx[a] = max(mx[a], b);
mn[a] = min(mn[a], b);
}
deque <pii> dq;
REP1(i, n){
while (!dq.empty() and mx[i] >= dq.back().F) dq.pop_back();
dq.push_back(mkp(mx[i], i));
if (dq.front().S + k <= i) dq.pop_front();
mx[i] = dq.front().F;
}
while (!dq.empty()) dq.pop_back();
for (int i=n;i;--i){
while (!dq.empty() and mn[i] <= dq.back().F) dq.pop_back();
dq.push_back(mkp(mn[i], i));
if (dq.front().S - k >= i) dq.pop_front();
mn[i] = dq.front().F;
}
seg[0].init(n, 1);
seg[1].init(n, 2);
cin >> q;
REP(q){
int s, t;
cin >> s >> t;
pii r = mkp(s, s);
int cnt = 0;
while (t < r.F or t > r.S){
++cnt;
pii nr = mkp(seg[1].query(r.F, r.S, 1, 1, n), seg[0].query(r.F, r.S, 1, 1, n));
if (r == nr){
cnt = -1;
break;
}
r = nr;
}
cout << cnt << '\n';
}
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(0);
solve();
return 0;
}
