#include <bits/stdc++.h>
using namespace std;
int n,k,m,q;
int a[200005],b[200005];
pair<int,int> v[20][100005];///intervalul in care pot ajunge din i facand 2^j pasi
int aintl[400005],aintr[400005];
int aintll[20][400005],aintrr[20][400005];
int lg[100005];
void build(int nod,int l,int r)
{
aintl[nod] = l;
aintr[nod] = r;
if (l != r)
{
int mij = (l + r) / 2;
build(2 * nod,l,mij);
build(2 * nod + 1,mij + 1,r);
}
}
void buildb(int nod,int l,int r,int b)
{
if (l == r)
{
aintl[nod] = v[b - 1][l].first;
aintr[nod] = v[b - 1][l].second;
}
else
{
int mij = (l + r) / 2;
buildb(2 * nod,l,mij,b);
buildb(2 * nod + 1,mij + 1,r,b);
aintl[nod] = min(aintl[2 * nod],aintl[2 * nod + 1]);
aintr[nod] = max(aintr[2 * nod],aintr[2 * nod + 1]);
}
}
void updater(int nod,int l,int r,int pos,int val)
{
if (l == r)
aintr[nod] = max(aintr[nod],val);
else
{
int mij = (l + r) / 2;
if (pos <= mij)
updater(2 * nod,l,mij,pos,val);
else
updater(2 * nod + 1,mij + 1,r,pos,val);
aintr[nod] = max(aintr[2 * nod],aintr[2 * nod + 1]);
}
}
void updatel(int nod,int l,int r,int pos,int val)
{
if (l == r)
aintl[nod] = min(aintl[nod],val);
else
{
int mij = (l + r) / 2;
if (pos <= mij)
updatel(2 * nod,l,mij,pos,val);
else
updatel(2 * nod + 1,mij + 1,r,pos,val);
aintl[nod] = min(aintl[2 * nod],aintl[2 * nod + 1]);
}
}
int queryr(int nod,int l,int r,int st,int dr)
{
if (r < st or dr < l)
return 0;
if (st <= l and r <= dr)
return aintr[nod];
int mij = (l + r) / 2;
return max(queryr(2 * nod,l,mij,st,dr),queryr(2 * nod + 1,mij + 1,r,st,dr));
}
int queryl(int nod,int l,int r,int st,int dr)
{
if (r < st or dr < l)
return n;
if (st <= l and r <= dr)
return aintl[nod];
int mij = (l + r) / 2;
return min(queryl(2 * nod,l,mij,st,dr),queryl(2 * nod + 1,mij + 1,r,st,dr));
}
void buildd(int nod,int l,int r,int b)
{
if (l == r)
{
aintll[b][nod] = v[b][l].first;
aintrr[b][nod] = v[b][l].second;
}
else
{
int mij = (l + r) / 2;
buildd(2 * nod,l,mij,b);
buildd(2 * nod + 1,mij + 1,r,b);
aintll[b][nod] = min(aintll[b][2 * nod],aintll[b][2 * nod + 1]);
aintrr[b][nod] = max(aintrr[b][2 * nod],aintrr[b][2 * nod + 1]);
}
}
int queryll(int nod,int l,int r,int st,int dr,int b)
{
if (r < st or dr < l)
return n;
if (st <= l and r <= dr)
return aintll[b][nod];
int mij = (l + r) / 2;
return min(queryll(2 * nod,l,mij,st,dr,b),queryll(2 * nod + 1,mij + 1,r,st,dr,b));
}
int queryrr(int nod,int l,int r,int st,int dr,int b)
{
if (r < st or dr < l)
return 0;
if (st <= l and r <= dr)
return aintrr[b][nod];
int mij = (l + r) / 2;
return max(queryrr(2 * nod,l,mij,st,dr,b),queryrr(2 * nod + 1,mij + 1,r,st,dr,b));
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
cin >> n >> k >> m;
for (int i = 2; i <= n; i++)
lg[i] = 1 + lg[i / 2];
for (int i = 1; i <= m; i++)
cin >> a[i] >> b[i];
build(1,1,n);
for (int i = 1; i <= m; i++)
{
if (a[i] < b[i])
updater(1,1,n,a[i],b[i]);
else
updatel(1,1,n,a[i],b[i]);
}
for (int i = 1; i <= n; i++)
{
v[0][i].first = queryl(1,1,n,i,min(n,i + k - 1));
v[0][i].second = queryr(1,1,n,max(1,i - k + 1),i);
}
/*for (int i = 1; i <= n; i++)
cout << v[0][i].first << ' ' << v[0][i].second << '\n';;
cout << '\n';*/
for (int b = 1; b <= lg[n]; b++)
{
///v[b][i].first = min(v[b - 1][j].first), unde j in intervalul v[b - 1][i]
///v[b][i].second = max(v[b - 1][j].second), unde j in intervalul v[b - 1][i]
buildb(1,1,n,b);
for (int i = 1; i <= n; i++)
{
int intl = v[b - 1][i].first,intr = v[b - 1][i].second;
//out << intl << ' ' << intr << "->";
v[b][i].first = queryl(1,1,n,intl,intr);
v[b][i].second = queryr(1,1,n,intl,intr);
}
/*for (int i = 1; i <= n; i++)
cout << v[b][i].first << ' ' << v[b][i].second << '\n';;
cout << '\n';*/
}
for (int b = 0; b <= lg[n]; b++)
{
buildd(1,1,n,b);
//cout << "yup" << endl;
}
cin >> q;
for (int i = 1; i <= q; i++)
{
int s,f;
cin >> s >> f;
int intl = s,intr = s;
int cost = 0;
for (int jump = lg[n]; jump >= 0; jump--)
{
int newintl = queryll(1,1,n,intl,intr,jump);
int newintr = queryrr(1,1,n,intl,intr,jump);
if (f < newintl or f > newintr)
{
intl = newintl;
intr = newintr;
cost += (1 << jump);
}
}
if (f < queryll(1,1,n,intl,intr,0) or f > queryrr(1,1,n,intl,intr,0))
cout << -1 << '\n';
else
cout << cost + 1 << '\n';
}
return 0;
}
