#include <bits/stdc++.h>
#define iter(a) a.begin(), a.end()
#define mp make_pair
#define F first
#define S second
#define eb emplace_back
#define lsort(a) sort(iter(a))
#define gsort(a) sort(iter(a), greater<>())
using namespace std;
typedef long long ll;
typedef double ld;
using pii = pair<int, int>;
ll iceil(ll a, ll b){
return (a + b - 1) / b;
}
#define lc (2 * id + 1)
#define rc (2 * id + 2)
int n;
struct Node{
pii mx = mp(-1, -1), tag = mp(-1, -1);
};
vector<Node> st;
void addtag(int id, pii v){
st[id].tag = max(st[id].tag, v);
st[id].mx = max(st[id].mx, v);
}
void push(int id){
addtag(lc, st[id].tag);
addtag(rc, st[id].tag);
st[id].tag = mp(-1, -1);
}
void pull(int id){
st[id].mx = max(st[lc].mx, st[rc].mx);
}
void modify(int l, int r, pii v, int L = 1, int R = n, int id = 0){
if(l <= L && R <= r){
addtag(id, v);
return;
}
push(id);
int M = (L + R) / 2;
if(r <= M) modify(l, r, v, L, M, lc);
else if(l > M) modify(l, r, v, M + 1, R, rc);
else{
modify(l, r, v, L, M, lc);
modify(l, r, v, M + 1, R, rc);
}
pull(id);
}
pii query(int l, int r, int L = 1, int R = n, int id = 0){
if(l <= L && R <= r) return st[id].mx;
push(id);
int M = (L + R) / 2;
if(r <= M) return query(l, r, L, M, lc);
else if(l > M) return query(l, r, M + 1, R, rc);
else return max(query(l, r, L, M, lc), query(l, r, M + 1, R, rc));
}
vector<vector<int>> anc;
vector<int> lb, rb;
int ts = 0;
const int SZ = 20;
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int K, m;
cin >> n >> K >> m;
rb.resize(m + 1);
anc.resize(SZ, vector<int>(m + 1));
lb.resize(m + 1);
rb.resize(m + 1);
st.resize(4 * n);
for(int i = 1; i <= m; i++) anc[0][i] = i;
for(int i = 1; i <= m; i++){
int l, r;
cin >> l >> r;
lb[i] = l; rb[i] = r;
modify(l, min(r - 1, l + K - 1), mp(r, i));
}
vector<int> best(n + 1);
for(int i = 1; i <= n; i++){
best[i] = query(i, i).S;
}
for(int i = 1; i <= m; i++){
int pr = query(lb[i], rb[i]).S;
if(pr == -1) continue;
//cerr << "pr " << i << " " << pr << "\n";
anc[0][i] = pr;
}
for(int i = 1; i < SZ; i++){
for(int j = 1; j <= m; j++){
anc[i][j] = anc[i - 1][anc[i - 1][j]];
}
}
int q;
cin >> q;
while(q--){
int s, t;
cin >> s >> t;
int now = best[s];
if(now == -1){
cout << "-1\n";
continue;
}
if(rb[now] >= t){
cout << "1\n";
continue;
}
int ans = 1;
for(int i = SZ - 1; i >= 0; i--){
if(rb[anc[i][now]] < t){
now = anc[i][now];
ans += 1 << i;
}
}
now = anc[0][now];
ans++;
if(rb[now] < t){
cout << "-1\n";
continue;
}
cout << ans << "\n";
}
return 0;
}
