#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define cerr if (false) cout
constexpr int mxN = 2e5, mxR = 25e3;
int N, R, Q, rgn[mxN];
vector<int> adj[mxN], rgnLst[mxR];
int tin[mxN], tout[mxN], timer;
void getTimes(int f) {
tin[f] = timer++;
for (int nf : adj[f]) {
getTimes(nf);
}
tout[f] = timer - 1;
}
int acnt[mxN];
void getacnt(int f, int t, int cur = 0) {
acnt[f] = cur;
cur += rgn[f] == t;
for (int nf : adj[f]) {
getacnt(nf, t, cur);
}
}
bool comp(int a, int b) {
return tin[a] < tin[b];
}
signed main() {
#ifdef cerr
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
#endif
cin >> N >> R >> Q >> rgn[0];
rgnLst[--rgn[0]].push_back(0);
for (int i = 1, a; i < N; i++) {
cin >> a >> rgn[i];
adj[--a].push_back(i);
rgnLst[--rgn[i]].push_back(i);
}
getTimes(0);
vector<int> big;
constexpr int BSZ = 447;
for (int i = 0; i < R; i++) {
if (rgnLst[i].size() > BSZ) {
big.push_back(i);
}
sort(rgnLst[i].begin(), rgnLst[i].end(), comp);
}
int ans[big.size()][R][2], psum[N];
memset(ans, 0, sizeof(ans));
for (int i = 0; i < big.size(); i++) { // O(sqrt(N) * (4 * N + R))
getacnt(0, big[i]);
memset(psum, 0, sizeof(psum));
for (int j : rgnLst[big[i]]) {
psum[tin[j]]++;
}
for (int j = 1; j < N; j++) {
psum[j] += psum[j-1];
}
for (int j = 0; j < R; j++) {
if (j == big[i]) continue;
for (int k : rgnLst[j]) {
ans[i][j][0] += acnt[k];
ans[i][j][1] += psum[tout[k]] - (tin[k] > 0 ? psum[tin[k]-1] : 0);
}
}
}
for (int q = 0, a, b; q < Q; q++) { // O(N * sqrt(N) * log_2(sqrt(N)))
cin >> a >> b;
a--, b--;
if (rgnLst[a].size() > BSZ) {
cout << ans[lower_bound(big.begin(),big.end(),a)-big.begin()][b][0] << '\n';
} else if (rgnLst[b].size() > BSZ) {
cout << ans[lower_bound(big.begin(),big.end(),b)-big.begin()][a][1] << '\n';
} else {
ll res = 0;
for (int i : rgnLst[a]) {
res += upper_bound(rgnLst[b].begin(), rgnLst[b].end(), tout[i], comp) - lower_bound(rgnLst[b].begin(), rgnLst[b].end(), tin[i], comp);
}
cout << res << '\n';
}
}
}
