/*
Take me to church
I'll worship like a dog at the shrine of your lies
I'll tell you my sins and you can sharpen your knife
Offer me that deathless death
Good God, let me give you my life
*/
#include<bits/stdc++.h>
using namespace std;
const int N = 200005, K = 25004, SQ = 400, QS = N / SQ + 5;
int n, k, q, ts, tc, T[N], St[N], Fn[N], Id[K], R[QS][K];
vector < int > Adj[N], A[N];
void DFS(int v)
{
St[v] = ts ++;
A[T[v]].push_back(v);
for (int u : Adj[v])
DFS(u);
Fn[v] = ts;
}
void DFS2(int v, int tp, int id, int cnt = 0)
{
if (T[v] == tp)
cnt ++;
else
R[id][T[v]] += cnt;
for (int u : Adj[v])
DFS2(u, tp, id, cnt);
}
inline bool CMP(int i, int j)
{
return (St[i] < St[j]);
}
int main()
{
scanf("%d%d%d%d", &n, &k, &q, &T[1]);
for (int i = 2, p; i <= n; i ++)
scanf("%d%d", &p, &T[i]), Adj[p].push_back(i);
DFS(1);
for (int i = 1; i <= k; i ++)
if ((int)A[i].size() >= SQ)
Id[i] = ++ tc, DFS2(1, i, tc);
for (; q; q --)
{
int v, u;
scanf("%d%d", &v, &u);
if ((int)A[v].size() >= SQ)
{
printf("%d\n", R[Id[v]][u]);
fflush(stdout);
continue;
}
int tot = 0;
for (int w : A[v])
St[0] = Fn[w], tot += (int)(lower_bound(A[u].begin(), A[u].end(), 0, CMP) - lower_bound(A[u].begin(), A[u].end(), w, CMP));
printf("%d\n", tot);
fflush(stdout);
}
return 0;
}
