#include <bits/stdc++.h>
using namespace std;
int n, r, q, cur = 0;
vector<int> h, s;
vector< vector<int> > g;
vector< vector< pair<int, int> > > reg;
int dfs(int u) {
int st = cur++;
int en = st;
for (auto& v : g[u]) {
en = dfs(v);
}
reg[h[u]].push_back({st, 1});
reg[h[u]].push_back({en, -1});
return en;
}
long long solve(int r1, int r2) {
int cur = 0, idx = -1;
long long ans = 0;
for (auto& p : reg[r2]) {
if (p.second == -1) {
continue;
}
while (idx + 1 < (int) reg[r1].size() && reg[r1][idx + 1].first < p.first) {
idx++;
cur += reg[r1][idx].second;
}
ans += (long long) cur;
}
return ans;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> r >> q;
h.resize(n + 1);
s.resize(n + 1);
cin >> h[1];
g.resize(n + 1);
for (int i = 2; i <= n; i++) {
cin >> s[i] >> h[i];
g[s[i]].push_back(i);
}
reg.resize(r + 1);
dfs(1);
for (int i = 1; i <= r; i++) {
sort(reg[i].begin(), reg[i].end());
}
while (q--) {
int r1, r2;
cin >> r1 >> r2;
cout << solve(r1, r2) << endl;
}
return 0;
}
