#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int B = 160;
int n, r, q, h[200200], p[200200];
int sz[200200], in[200200], out[200200], cnt, lev[200200], head[200200], rev[200200];
vector<int> v[200200], rv[30030], lb[30030];
int dfs_size(int u) {
for(auto &x : v[u]) {
sz[u] += dfs_size(x);
if(sz[x] > sz[v[u][0]]) swap(x, v[u][0]);
}
return ++sz[u];
}
void dfs_hld(int u) {
in[u] = ++cnt, lev[u] = lev[p[u]]+1;
for(auto x : v[u]) {
head[x] = (x == v[u][0] ? head[u] : x);
dfs_hld(x);
}
out[u] = cnt;
}
int main(){
cin.tie(0)->sync_with_stdio(0);
cin >> n >> r >> q >> h[1];
for(int i=2;i<=n;i++) cin >> p[i] >> h[i];
for(int i=1;i<=n;i++) v[p[i]].push_back(i);
head[1] = 1, dfs_size(1), dfs_hld(1);
for(int i=1;i<=n;i++) rv[h[i]].push_back(in[i]), rev[in[i]] = i;
for(int i=1;i<=r;i++) sort(rv[i].begin(), rv[i].end());
for(int i=1;i<=r;i++) if(rv[i].size() >= B) {
lb[i].resize(n+1, 0);
for(int j=0, k=0;j<=n;j++) {
while(k < rv[i].size() && rv[i][k] <= j) k++;
lb[i][j] = k;
}
}
map<pair<int, int>, int> mp;
while(q--) {
int a, b; cin >> a >> b;
if(mp.count({a, b})) { cout << mp[{a, b}] << endl; continue; }
auto &ans = mp[{a, b}];
if(rv[a].size() <= rv[b].size()) {
for(auto x : rv[a]) {
int L = x, R = out[rev[x]];
if(!lb[b].empty()) ans += lb[b][R]-lb[b][L-1];
else for(auto y : rv[b]) if(L <= y && y <= R) ans++;
}
} else {
for(auto x : rv[b]) {
int u = rev[x];
while(u) {
int L = in[head[u]], R = in[u]; u = p[head[u]];
if(!lb[a].empty()) ans += lb[a][R]-lb[a][L-1];
else for(auto y : rv[a]) if(L <= y && y <= R) ans++;
}
}
}
cout << ans << endl;
}
}
