#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
ll min(ll a , ll b)
{
if(a < b)return a;
return b;
}
ll max(ll a , ll b)
{
if(a > b)return a;
return b;
}
const ll maxn = 200052, max_SQRT = 125; // la la lay lay
ll N, R, Q, H[maxn], rgnOrd[maxn >> 3], revOrd[maxn >> 3];
vector<ll> adj[maxn], rgnLst[maxn >> 3], rgnLst2[maxn >> 3];
ll timer, tin[maxn], tout[maxn];
ll tdall[max_SQRT][max_SQRT], td[maxn][max_SQRT];
void dfs(ll f)
{
tin[f] = timer++;
for (ll i = 0; i < min(R, max_SQRT) && revOrd[H[f]] < max_SQRT; i++)
{
tdall[revOrd[H[f]]][i] += td[f][i];
}
for (ll nf : adj[f])
{
for (ll i = 0; i < min(R, max_SQRT); i++)
{
td[nf][i] = td[f][i] + (rgnOrd[i] == H[f]);
}
dfs(nf);
}
tout[f] = timer - 1;
}
signed main()
{
scanf("%lli%lli%lli%lli", &N, &R, &Q, &H[0]);
rgnLst[--H[0]].push_back(0);
for (ll i = 1, p; i < N; i++)
{
scanf("%lli%lli", &p, &H[i]);
adj[--p].push_back(i);
rgnLst[--H[i]].push_back(i);
}
iota(rgnOrd, rgnOrd + R, 0);
sort(rgnOrd, rgnOrd + R, [&](const ll &a, const ll &b)
{ return rgnLst[a].size() > rgnLst[b].size(); });
for (ll i = 0; i < R; i++)
{
revOrd[rgnOrd[i]] = i;
}
dfs(0);
for (ll i = 0; i < R; i++)
{
for (ll j : rgnLst[i])
{
rgnLst2[i].push_back(tin[j]);
}
sort(rgnLst2[i].begin(), rgnLst2[i].end());
}
for (ll a, b, ans; Q--;)
{
scanf("%lli%lli", &a, &b);
a--, b--;
ans = 0;
if (revOrd[a] < max_SQRT && revOrd[b] < max_SQRT)
{
ans = tdall[revOrd[b]][revOrd[a]];
}
else if (revOrd[a] < max_SQRT)
{
for (ll i : rgnLst[b])
{
ans += td[i][revOrd[a]];
}
}
else
{
for (ll i : rgnLst[a])
{
ans += upper_bound(rgnLst2[b].begin(), rgnLst2[b].end(), tout[i]) - lower_bound(rgnLst2[b].begin(), rgnLst2[b].end(), tin[i]);
}
}
printf("%lli\n", ans);
}
}
/*
ZZZZZZZ A M M IIIIIII N N TTTTTTTTTT RRRRRR EEEEEEE EEEEEEE
Z A A M M M M I NN N TT R R E E
Z A A M M M M I N N N TT R R E E
Z AAAAAAA M M M I N N N TT RRRRRR EEEEEEE EEEEEEE
Z A A M M I N N N TT RR E E
Z A A M M I N NN TT R R E E
ZZZZZZZ A A M M IIIIIII N N TT R R EEEEEEE EEEEEEE
*/
