#include <bits/stdc++.h>
#ifdef NON_SUBMIT
#define TEST(n) (n)
#define tout cerr
#else
#define TEST(n) ((void)0)
#define tout cin
#endif
using namespace std;
const int rt=500;
vector<int> adj[200000], R[25000], O;
int node_cnt=-1, RV[200000], num[200000], fin[200000], sum[rt][200000], sum2[rt][200000], tree[200001], idx[200000];
long long ans1[rt][25000], ans2[rt][25000];
void add_tree(int n, int v)
{
for(++n;n<=200000;n+=n&-n) tree[n]+=v;
}
int get_sum(int n)
{
int ret=0;
for(++n;n;n-=n&-n) ret+=tree[n];
return ret;
}
int get_sum(int s, int e)
{
return get_sum(e)-get_sum(s-1);
}
void dfs(int c)
{
num[c]=++node_cnt;
for(auto n: adj[c]) dfs(n);
fin[c]=node_cnt;
}
void dfs2(int c, int idx)
{
if(RV[c]==O[idx]) {
sum[idx][c]++;
sum2[idx][c]++;
}
for(auto n: adj[c]) {
sum[idx][n]=sum[idx][c];
dfs2(n,idx);
sum2[idx][c]+=sum2[idx][n];
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(NULL); cout.tie(NULL);
TEST(freopen("input.txt","r",stdin));
TEST(freopen("output.txt","w",stdout));
TEST(freopen("debug.txt","w",stderr));
int N, M, Q, p;
cin>>N>>M>>Q>>RV[0];
R[--RV[0]].push_back(0);
for(int i=1;i<N;i++) {
cin>>p>>RV[i];
adj[--p].push_back(i);
R[--RV[i]].push_back(i);
}
dfs(0);
for(int i=0;i<M;i++) if(R[i].size()>=rt) {
idx[i]=O.size();
O.push_back(i);
dfs2(0,O.size()-1);
}
for(int i=0;i<O.size();i++) for(int j=0;j<N;j++) {
ans1[i][RV[j]]+=sum[i][j];
ans2[i][RV[j]]+=sum2[i][j];
}
while(Q--) {
int a, b;
cin>>a>>b; --a; --b;
if(R[a].size()>=rt) cout<<ans1[idx[a]][b]<<'\n';
else if(R[b].size()>=rt) cout<<ans2[idx[b]][a]<<'\n';
else {
long long ans=0;
for(auto r: R[b]) add_tree(num[r],1);
for(auto r: R[a]) ans+=get_sum(num[r],fin[r]);
for(auto r: R[b]) add_tree(num[r],-1);
cout<<ans<<'\n';
}
cout.flush();
}
return 0;
}
