// submitting julia_08's solution
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAXN = 2e5 + 10;
const int MAXR = 3e4 + 10;
int region[MAXN], pai[MAXN];
vector<int> adj[MAXN];
vector<int> regions_pre[MAXN], regions_pos[MAXN];
int pre[MAXN], pos[MAXN];
int n, r, q;
int t = 0;
void dfs(int v){
pre[v] = ++ t;
for(auto u : adj[v]){
if(u != pai[v]) dfs(u);
}
pos[v] = t;
}
int main(){
cin.tie(0)->sync_with_stdio(0);
cin >> n >> r >> q;
cin >> region[1];
for(int i=2; i<=n; i++){
cin >> pai[i] >> region[i];
adj[pai[i]].push_back(i);
}
dfs(1);
for(int i=1; i<=n; i++){
regions_pre[region[i]].push_back(pre[i]);
regions_pos[region[i]].push_back(pos[i]);
}
for(int i=1; i<=r; i++){
sort(regions_pre[i].begin(), regions_pre[i].end());
sort(regions_pos[i].begin(), regions_pos[i].end());
}
while(q--){
int r1, r2; cin >> r1 >> r2;
ll ans = 0;
/*cout << "pre: " << r1 << " = ";
for(auto x : regions_pre[r1]) cout << x << " ";
cout << "\n";
cout << "pos: " << r1 << " = ";
for(auto x : regions_pos[r1]) cout << x << " " ;
cout << "\n";
cout << "pre: " << r2 << " = ";
for(auto x : regions_pre[r2]) cout << x << " ";
cout << "\n";
cout << "pos: " << r2 << " = ";
for(auto x : regions_pos[r2]) cout << x << " " ;
cout << "\n";*/
int l = -1;
for(int i=0; i<regions_pos[r1].size(); i++){
while(l + 1 < (int) regions_pre[r2].size() && regions_pre[r2][l + 1] <= regions_pos[r1][i]) l ++;
// cout << i << ": " << regions_pos[r1][i] << "\n";
// cout << "l = " << l << " " << regions_pre[r2][l + 1] << "\n";
ans += (l + 1);
} // soma os caras com pre maior
l = -1;
for(int i=0; i<regions_pre[r1].size(); i++){
while(l + 1 < (int) regions_pre[r2].size() && regions_pre[r2][l + 1] < regions_pre[r1][i]) l ++;
// cout << i << ": " << regions_pre[r1][i] << "\n";
// cout << "l = " << l << "\n";
ans -= (l + 1);
} // subtrai os caras com pos menor
cout << ans << endl;
}
return 0;
}
