#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
#define pb push_back
const int maxn = 200001;
vector<int> adj[maxn];
int st[maxn], en[maxn];
int timer = 0;
void dfs(int s, int p){
st[s] = timer++;
for(auto u: adj[s]){
if(u == p) continue;
dfs(u, s);
}
en[s] = timer;
}
bool anc(int a, int b){
return st[a] <= st[b] and en[b] <= en[a];
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
int N, R, Q; cin >> N >> R >> Q;
vector<int> reg[R+1];
int h; cin >> h;
reg[h].pb(1);
for(int i=2; i<=N; i++){
int p, r; cin >> p >> r;
adj[i].pb(p); adj[p].pb(i);
reg[r].pb(i);
}
dfs(1, 0);
while(Q--){
int r1, r2; cin >> r1 >> r2;
int ans = 0;
for(auto a: reg[r1]){
for(auto b: reg[r2]){
if(anc(a, b)) ans++;
}
}
cout << ans << "\n";
cout.flush();
}
}
