#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ordered_set tree <int, null_type, less < int >, rb_tree_tag, tree_order_statistics_node_update >
typedef long long ll;
const int N = 200003;
const int B = 300;
ll k;
ll dp[N], cnt[N / B][25002], up[N / B][25002];
int n, m, q, tick, cur, num;
int a[N], p[N], tin[N], tout[N], id[N];
vector < int > g[N], r[N];
ordered_set st;
void dfs(int v){
tin[v] = ++tick;
for(int u : g[v]) dfs(u);
tout[v] = ++tick;
}
void calc(int v, int tp){
cnt[id[tp]][a[v]] += cur;
if(a[v] == tp) cur++;
for(int u : g[v]) calc(u, tp), dp[v] += dp[u];
if(a[v] == tp) cur--;
up[id[tp]][a[v]] += dp[v] - (a[v] == tp);
}
bool cmp(int i, int j){
return tin[i] < tin[j];
}
void solve(){
cin >> n >> m >> q >> a[1], r[a[1]].push_back(1);
for(int i = 2; i <= n; i++) cin >> p[i] >> a[i], g[p[i]].push_back(i), r[a[i]].push_back(i);
dfs(1);
for(int i = 1; i <= m; i++){
if(r[i].size() > B){
for(ll x : r[i]) dp[x] = 1;
id[i] = ++num, calc(1, i);
fill(dp, dp + n + 1, 0);
}
else{
sort(r[i].begin(), r[i].end(), cmp);
}
}
while(q--){
int r1, r2, i = 0;
cin >> r1 >> r2;
if(r[r1].size() > B) cout << cnt[id[r1]][r2] << endl;
else if(r[r2].size() > B) cout << up[id[r2]][r1] << endl;
else{
k = 0, st.clear();
for(int x : r[r2]) st.insert(tout[x]);
for(int x : r[r1]){
while(i < r[r2].size() && tin[r[r2][i]] < tin[x]) st.erase(tout[r[r2][i]]), i++;
k += st.order_of_key(tout[x]);
}
cout << k << endl;
}
}
}
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int tt = 1;
// cin >> tt;
while(tt--) solve();
}
