#include<bits/stdc++.h>
using namespace std;
#define task "a"
#define se second
#define fi first
#define ll long long
#define ii pair<int, int>
const long mxN = 2e5 + 7, inf = 1e9 + 7;
ii lazy[mxN * 4], tree[mxN * 4][20], rng[mxN * 4][20];
int n, m;
void Gen(int j = 1, int l = 1, int r = n)
{
lazy[j].fi = inf;
lazy[j].se = 0;
if (l == r)
{
lazy[j].fi = lazy[j].se = l;
return;
}
int mid = (l + r) / 2;
Gen(j * 2, l, mid);
Gen(j * 2 + 1, mid + 1, r);
}
void Upd(int u, int v, int nw, int j = 1, int l = 1, int r = n)
{
if (r < u || v < l)
return;
if (u <= l && r <= v)
{
lazy[j].fi = min(lazy[j].fi, nw);
lazy[j].se = max(lazy[j].se, nw);
return;
}
int mid = (l + r) / 2;
Upd(u, v, nw, j * 2, l, mid);
Upd(u, v, nw, j * 2 + 1, mid + 1, r);
}
ii cmp(ii u, ii v)
{
u.fi = min(u.fi, v.fi);
u.se = max(u.se, v.se);
return u;
}
void Down(int j = 1, int l = 1, int r = n)
{
if (l == r)
{
rng[l][0] = lazy[j];
return;
}
lazy[j * 2] = cmp(lazy[j * 2], lazy[j]);
lazy[j * 2 + 1] = cmp(lazy[j * 2 + 1], lazy[j]);
int mid = (l + r) / 2;
Down(j * 2, l, mid);
Down(j * 2 + 1, mid + 1, r);
}
void Build(int id, int j = 1, int l = 1, int r = n)
{
if (l == r)
{
tree[j][id] = rng[l][id];
return;
}
int mid = (l + r) / 2;
Build(id, j * 2, l, mid);
Build(id, j * 2 + 1, mid + 1, r);
tree[j][id] = cmp(tree[j * 2][id], tree[j * 2 + 1][id]);
}
ii Get(int id, int u, int v, int j = 1, int l = 1, int r = n)
{
if (r < u || v < l)
return {inf, 0};
if (u <= l && r <= v)
return tree[j][id];
int mid = (l + r) / 2;
return cmp(Get(id, u, v, j * 2, l, mid), Get(id, u, v, j * 2 + 1, mid + 1, r));
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
//freopen(task".INP", "r", stdin);
//freopen(task".OUT", "w", stdout);
int k;
cin >> n >> k;
cin >> m;
k--;
Gen();
for (int i = 1; i <= m; i++)
{
int u, v;
cin >> u >> v;
if (u < v)
Upd(u, min(u + k, v), v);
else
Upd(max(u - k, v), u, v);
}
Down();
Build(0);
for (int lg = 1; lg <= 18; lg++)
{
for (int i = 1; i <= n; i++)
rng[i][lg] = Get(lg - 1, rng[i][lg - 1].fi, rng[i][lg - 1].se);
Build(lg);
}
int q;
cin >> q;
for (int i = 1; i <= q; i++)
{
int u, v;
cin >> u >> v;
int l = u, r = u, base = 0, ans = inf;
for (int j = 18; j >= 0; j--)
{
ii tmp = Get(j, l, r);
if (tmp.fi <= v && v <= tmp.se)
ans = base + (1 << j);
else
{
l = tmp.fi;
r = tmp.se;
base += (1 << j);
}
}
if (ans >= inf)
cout << -1 << '\n';
else
cout << ans << '\n';
}
}
