#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i, a, b) for(int i=(a), _b=(b); i<=_b; i++)
#define FORD(i, a, b) for(int i=(a), _b=(b); i>=_b; i--)
#define BIT(i, j) ((i>>j)&1)
#define pb push_back
#define ii pair<ll, ll>
#define pii pair<ll, ii>
#define all(x) x.begin(), x.end()
#define fi first
#define se second
const ll inf = 1e18;
const ll mod = 1e9+7;
const ll N = 100005;
const ll M = 50005;
int n, m, k, q, L[20][N], R[20][N];
ii st[20][4 * N];
ii getP(ii a, ii b)
{
return {min(a.fi, b.fi), max(a.se, b.se)};
}
void build (int type, int id = 1, int l = 1, int r = n)
{
if (l == r)
{
st[type][id] = {L[type][l], R[type][l]};
return;
}
int mid = l + r >> 1;
build (type, id << 1, l, mid);
build (type, id << 1 | 1, mid + 1, r);
st[type][id] = getP(st[type][id << 1], st[type][id << 1 | 1]);
}
ii get (int type, int u, int v, int id = 1, int l = 1, int r = n)
{
if (v < l || u > r) return {n + 1, 0};
if (u <= l && r <= v) return st[type][id];
int mid = l + r >> 1;
ii x = get (type, u, v, id << 1, l, mid);
ii y = get (type, u, v, id << 1 | 1, mid + 1, r);
return getP(x, y);
}
void solve()
{
cin >> n >> k >> m;
for (int i = 0; i <= 18; i++)
for (int j = 1; j <= n; j++)
L[i][j] = R[i][j] = j;
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);
for (int i = 1; i <= n; i++)
{
auto [u, v] = get (0, max(1, i - k + 1), i);
R[0][i] = v;
auto [x, y] = get (0, i, min(n, i + k - 1));
L[0][i] = x;
//.cout << L[0][i] << ' ' << R[0][i] << '\n';
}
build(0);
for (int i = 1; i <= 18; i++)
{
for (int j = 1; j <= n; j++)
{
auto [u, v] = get (i - 1, L[i - 1][j], R[i - 1][j]);
L[i][j] = u;
R[i][j] = v;
}
build (i);
}
cin >> q;
while (q--)
{
int s, t;
cin >> s >> t;
ll ans = 0;
int l = s, r = s;
for (int i = 18; i >= 0; i--)
{
auto [u, v] = get(i, l, r);
if (t < u || t > v)
{
l = u, r = v;
ans += (1 << i);
}
}
auto [u, v] = get (0, l, r);
if (u <= t && v >= t)
{
cout << ans + 1 << '\n';
}
else cout << -1 << '\n';
}
}
int 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);
}
solve();
return 0;
}
