#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl
#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)
template<typename T>
void amin(T &a, T b) {
a = min(a,b);
}
template<typename T>
void amax(T &a, T b) {
a = max(a,b);
}
#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif
/*
refs:
https://codeforces.com/blog/entry/99837?#comment-886479
*/
const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;
const int LOG = 18;
template<typename T>
struct segtree {
// https://codeforces.com/blog/entry/18051
/*=======================================================*/
struct data {
int a;
};
data neutral = {-inf1};
data merge(data &left, data &right) {
data curr;
curr.a = max(left.a,right.a);
return curr;
}
void create(int i, T v) {
tr[i].a = v;
}
void modify(int i, T v) {
tr[i].a = v;
}
/*=======================================================*/
int n;
vector<data> tr;
segtree() {
}
segtree(int siz) {
init(siz);
}
void init(int siz) {
n = siz;
tr.assign(2 * n, neutral);
}
void build(vector<T> &a, int siz) {
rep(i, siz) create(i + n, a[i]);
rev(i, n - 1, 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
}
void pupd(int i, T v) {
modify(i + n, v);
for (i = (i + n) >> 1; i; i >>= 1) tr[i] = merge(tr[i << 1], tr[i << 1 | 1]);
}
data query(int l, int r) {
data resl = neutral, resr = neutral;
for (l += n, r += n; l <= r; l >>= 1, r >>= 1) {
if (l & 1) resl = merge(resl, tr[l++]);
if (!(r & 1)) resr = merge(tr[r--], resr);
}
return merge(resl, resr);
}
};
void solve(int test_case)
{
int n,k,m; cin >> n >> k >> m;
vector<pii> a(m+5);
rep1(i,m) cin >> a[i].ff >> a[i].ss;
vector<int> enter[n+5], leave[n+5];
rep1(i,m){
auto [l,r] = a[i];
amin(r,l+k-1);
enter[l].pb(a[i].ss);
leave[r+1].pb(a[i].ss);
}
int up[n+5][LOG];
multiset<int> ms;
ms.insert(0);
rep1(i,n){
trav(r,enter[i]){
ms.insert(r);
}
trav(r,leave[i]){
ms.erase(ms.find(r));
}
up[i][0] = max(*ms.rbegin(),i);
}
rep1(j,LOG-1){
segtree<int> seg(n+5);
vector<int> prev_jump(n+5);
rep1(i,n) prev_jump[i] = up[i][j-1];
seg.build(prev_jump,n+1);
rep1(i,n){
up[i][j] = seg.query(i,up[i][j-1]).a;
}
}
segtree<int> seg[LOG];
rep(j,LOG){
seg[j] = segtree<int>(n+5);
vector<int> jump(n+5);
rep1(i,n) jump[i] = up[i][j];
seg[j].build(jump,n+1);
}
int q; cin >> q;
while(q--){
int s,t; cin >> s >> t;
if(up[s][LOG-1] < t){
cout << -1 << endl;
conts;
}
int rx = s;
int ans = 0;
rev(j,LOG-1,0){
int mx_reach = seg[j].query(s,rx).a;
if(mx_reach < t){
ans += 1<<j;
rx = mx_reach;
}
}
ans++;
cout << ans << endl;
}
}
int main()
{
fastio;
int t = 1;
// cin >> t;
rep1(i, t) {
solve(i);
}
return 0;
}
