#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ii pair<int,int>
#define fir first
#define sec second
#define pb push_back
const int maxn=2e5;
const int block=250;
int n,r,qu,root;
vector<int>adj[maxn+2];
int reg[maxn+2];
int in[maxn+2],out[maxn+2],rev[maxn+2];
int cnt;
vector<int>mana[maxn+2];
void euler(int cur){
in[cur]=++cnt;
rev[cnt]=cur;
mana[reg[cur]].pb(cnt);
for(auto x : adj[cur]){
euler(x);
}
out[cur]=cnt;
}
map<int,int>ans[maxn+2];
void dfs(int cur,int mau,int tot){
ans[mau][reg[cur]]+=tot;
if(reg[cur]==mau){
tot++;
}
for(auto x : adj[cur]){
dfs(x,mau,tot);
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
cin>>n>>r>>qu>>reg[1];
for(int q=2;q<=n;q++){
int p;
cin>>p>>reg[q];
adj[p].pb(q);
}
euler(1);
for(int q=1;q<=n;q++){
if(mana[q].size()>=block){
dfs(1,q,0);
}
}
while(qu--){
int a,b;
cin>>a>>b;
if(mana[a].size()>=block){
cout<<ans[a][b]<<endl;
}
else{
int tot=0;
for(auto x : mana[a]){
x=rev[x];
int lst=upper_bound(mana[b].begin(),mana[b].end(),out[x])-mana[b].begin();
int mul=upper_bound(mana[b].begin(),mana[b].end(),in[x])-mana[b].begin();
tot+=(lst-mul);
}
cout<<tot<<endl;
}
}
}
