#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int N = 2e5 + 5;
const int R = 25005;
const int S = 30000;
int n, r, q, in[N], out[N], T = 0;
vector<int> g[N], reg[R];
map<pair<int,int>,int> mp;
vector<int> Spe;
int bit[N];
void dfs(int x,int p = 0){
in[x] = ++T;
for(int j : g[x]) if(j != p){
dfs(j,x);
}
out[x] = T;
}
void upd(int idx,int val){
for(;idx <= T ; idx += (idx & (-idx))) bit[idx] += val;
}
int get(int idx){
ll s = 0;
for(;idx ;idx -= (idx & (-idx))) s += bit[idx];
return s;
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);
cin >> n >> r >> q;
int x,y; cin >> x; reg[x].push_back(1);
for(int i = 2 ; i <= n ; ++i){
cin >> x >> y;
g[x].push_back(i);
reg[y].push_back(i);
}
dfs(1);
for(int i = 1 ; i <= r ; ++i)
if((int)reg[i].size() >= S) Spe.push_back(i);
for(int i : Spe){
for(int l : reg[i]) {
upd(in[l],1);
upd(out[l] + 1,-1);
}
for(int j = 1 ; j <= n ; ++j){
int ans = 0;
for(int l : reg[j]) ans += get(in[l]) - (i == j);
mp[{i,j}] = ans;
}
for(int l : reg[i]) upd(out[l] + 1,1);
for(int j = 1 ; j <= n ; ++j){
int ans = 0;
for(int l : reg[j]) ans += get(out[l]) - get(in[l]) - (i == j);
mp[{j,i}] = ans;
}
for(int l : reg[i]) upd(in[l],-1);
}
int u, v;
while(q--){
cin >> u >> v;
if(mp.count({u,v})) {cout << mp[{u,v}]<< endl; continue;}
//cout << "?\n";
for(int j : reg[u]) {
//cout << j << '.' << in[j] << ' ' << out[j] << '\n';
upd(in[j],1);
upd(out[j] + 1,-1);
}
//cout << "??\n";
int ans = 0;
for(int j : reg[v])
ans += get(in[j]) - (u == v);
//cout << "???\n";
for(int j : reg[u]) upd(out[j] + 1,1);
mp[{u,v}] = ans;
cout << ans << endl;
if(u != v){
ans = 0;
for(int j : reg[v]) ans += get(out[j]) - get(in[j]);
mp[{v,u}] = ans;
}
for(int j : reg[u]) upd(in[j],-1);
}
return 0;
}
