#include <bits/stdc++.h>
#define REP(v, i, j) for (int v = i; v != j; v++)
#define FORI(v) for (auto i : v)
#define FORJ(v) for (auto j : v)
#define OUT(v, a) \
FORI(v) \
cout << i << a;
#define OUTS(v, a, b) \
cout << v.size() << a; \
OUT(v, b)
#define in(a, n) \
REP(i, 0, n) \
cin >> a[i];
#define SORT(v) sort(begin(v), end(v))
#define REV(v) reverse(begin(v), end(v))
#define MEMSET(m) memset(m, -1, sizeof m)
#define pb push_back
#define fi first
#define se second
#define detachIO \
ios_base::sync_with_stdio(false); \
cin.tie(0); \
cout.tie(0);
using namespace std;
template<typename _Tp, typename _Alloc = std::allocator<_Tp> >
bool operator==(const vector<_Tp, _Alloc>& __x, const vector<_Tp, _Alloc>& __y) {
if(__x.size() != __y.size()) return false;
return std::equal(__x.begin(), __x.end(), __y.begin());
}
typedef pair<int, int> pii;
typedef pair<pii, int> piii;
typedef pair<pii, pii> piiii;
const int MOD = 1e9+7;
struct modint {
long long val;
modint() = default;
modint(int _val): val(_val){}
modint operator+(modint b){ return ((this->val + b.val)%MOD); }
modint operator-(modint b){ return ((MOD + this->val - b.val)%MOD); }
modint operator*(modint b){ return ((this->val * b.val)%MOD); }
modint operator^(int a){
if(a==0)return 1;
if(a==1)return *this;
return (((*this)*(*this))^(a>>1))*((*this)^(a&1));
}
};
modint invert(modint a){
return a^(MOD-2);
}
modint operator/(modint a, modint b){
return a*invert(b);
}
struct segment_tree {
long long n;
typedef pii T;
vector<T> seg;
const T e = {-1,0};
T merge(T a, T b){
if(b==e)return a;
if(a.fi > b.fi)return a;
return b;
}
segment_tree(long long _n): n(_n),seg(4*_n+10,e) /** BUG: GCC does not initialize the elements properly this way */ {
for(auto &i:seg)i=e;
}
void update(long long pos, long long l, long long r, long long idx, T val){
if(r<idx)return;
if(l>idx)return;
if(l==r){
seg[pos]=val;
return;
}
update(pos*2+1,l,(l+r)/2,idx,val);
update(pos*2+2,((l+r)/2)+1,r,idx,val);
seg[pos]=merge(seg[pos*2+1],seg[pos*2+2]);
}
T query(long long pos, long long l, long long r, long long ql, long long qr){
if(l > qr)return e;
if(ql > r)return e;
if(ql <= l && r <= qr)return seg[pos];
if(l==r)return e;
return merge(query(pos*2+1,l,(l+r)/2,ql,qr),query(pos*2+2,((l+r)/2)+1,r,ql,qr));
}
};
int r[200100];
int j[200100];
int b[200100][30];
vector<pii> s[200100];
vector<pii> e[200100];
int main(){
detachIO;
int n;cin>>n;
int k;cin>>k;
int m;cin>>m;
vector<pii> vec;
REP(i,0,m){
int a,b;cin>>a>>b;
assert(a<b);
vec.pb({a,b});
s[a].pb({b,i});
e[min(b+1,a+k)].pb({b,i});
}
SORT(vec);
set<pii> st;
segment_tree tree(n+10);
REP(i,1,n+1){
FORJ(s[i])st.insert(j);
FORJ(e[i])st.erase(j);
r[i]=i;
if(st.size())r[i]=st.rbegin()->fi;
// cerr<<r[i]<<" ";
tree.update(0,0,n,i-1,{r[i],i});
}
// cerr<<endl;
REP(i,1,n+1){
j[i]=b[i][0]=tree.query(0,0,n,i-1,r[i]-1).se;
// cerr<<j[i]<<" ";
}
REP(x,1,25){
REP(i,1,n+1){
b[i][x]=b[b[i][x-1]][x-1];
}
}
int q;cin>>q;
while(q--){
int s,t;cin>>s>>t;
int ans=0;
REP(xx,0,25){
int x=24-xx;
if(r[s]>=t)break;
if(r[b[s][x]]<t)s=b[s][x],ans+=(1<<x);
}
while(r[s]<t){
s=j[s],ans++;
if(j[s]==s)break;
}
ans++;
if(r[s]<t)cout<<"-1\n";
else cout<<ans<<'\n';
}
}
