#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll, ll>
#define pii pair<int, int>
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define Unique(v) sort(all(v)); (v).erase(unique(all(v)), (v).end());
const int N = 1e5 + 5;
int n, k, m, q;
int L[20][N], R[20][N];
pii st[20][4 * N];
pii GET(pii a, pii b) {
return {min(a.fi, b.fi), max(a.se, b.se)};
}
void build(int lg, int id, int l, int r) {
if (l == r) {
st[lg][id] = {L[lg][l], R[lg][l]};
return;
}
int mid = l + r >> 1;
build(lg, id << 1, l, mid);
build(lg, id << 1 | 1, mid + 1, r);
st[lg][id] = GET(st[lg][id << 1], st[lg][id << 1 | 1]);
}
pii get(int lg, int id, int l, int r, int u, int v) {
if (v < l || r < u) return {n + 1, 0};
if (u <= l && r <= v) return st[lg][id];
int mid = l + r >> 1;
return GET(get(lg, id << 1, l, mid, u, v), get(lg, id << 1 | 1, mid + 1, r, u, v));
}
signed main() {
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define task "task"
if (fopen(task".INP", "r")) {
freopen(task".INP", "r", stdin);
freopen(task".OUT", "w", stdout);
}
if (fopen("task.INP", "r")) {
freopen("task.INP", "r", stdin);
freopen("task.OUT", "w", stdout);
}
cin>>n>>k>>m;
for (int i = 1; i <= n; i++)
for (int j = 0; j < 18; j++)
L[j][i] = R[j][i] = i;
for (int i = 1; i <= m; i++) {
int a, b; cin>>a>>b;
L[0][a] = min(L[0][a], b);
R[0][a] = max(R[0][a], b);
}
build(0, 1, 1, n);
for (int i = 1; i <= n; i++) {
auto [u, v] = get(0, 1, 1, n, max(1, i - k + 1), i);
R[0][i] = v;
auto [x, y] = get(0, 1, 1, n, i, min(n, i + k - 1));
L[0][i] = x;
}
build(0, 1, 1, n);
for (int lg = 1; lg < 18; lg++) {
for (int i = 1; i <= n; i++) {
auto [u, v] = get(lg - 1, 1, 1, n, L[lg - 1][i], R[lg - 1][i]);
L[lg][i] = u; R[lg][i] = v;
}
build(lg, 1, 1, n);
}
cin>>q;
while (q--) {
int s, t; cin>>s>>t;
int _l = s, _r = s;
int ans = 0;
for (int i = 17; i >= 0; i--) {
auto [u, v] = get(i, 1, 1, n, _l, _r);
if (t < u || v < t) {
ans += 1 << i;
_l = u, _r = v;
}
}
auto [u, v] = get(0, 1, 1, n, _l, _r);
if (u <= t && t <= v) cout<<ans + 1<<'\n';
else cout<<-1<<'\n';
}
cerr<<setprecision(3)<<fixed<<"Time elapsed: "<< 1.0 * clock() / CLOCKS_PER_SEC <<"s\n";
}
