#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define ordered_set tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
struct Centroid {
vector<vector<int>> adj;
vector<vector<pair<int, int>>> org;
vector<int> pa;
Centroid(int N): sz(N), vis(N), org(N), adj(N), pa(N) {}
void add_edge(int a, int b, int w) {
org[a].emplace_back(b, w);
org[b].emplace_back(a, w);
}
int build_tree(int now, int prv = 0) {
now = get_centroid(now, prv, get_sz(now));
vis[now] = 1;
pa[now] = prv;
for (auto [nxt, w] : org[now]) {
if (vis[nxt]) continue;
nxt = build_tree(nxt, now);
adj[now].push_back(nxt);
adj[nxt].push_back(now);
}
return now;
}
private:
vector<int> sz;
vector<char> vis;
int get_sz(int now, int prv = 0) {
sz[now] = 1;
for (auto [nxt, w] : org[now]) {
if (nxt == prv || vis[nxt]) continue;
sz[now] += get_sz(nxt, now);
}
return sz[now];
}
int get_centroid(int now, int prv, int S) {
for (auto [nxt, w] : org[now]) {
if (nxt == prv || vis[nxt] || sz[nxt] * 2 <= S) continue;
return get_centroid(nxt, now, S);
}
return now;
}
};
int main() {
cin.sync_with_stdio(false);
cin.tie(nullptr);
int N, M;
long K;
cin >> N >> M >> K;
Centroid cent(N + 1);
for (int R, D, i = 2; i <= N; ++i) {
cin >> R >> D;
cent.add_edge(i, R, D);
}
int root = cent.build_tree(1);
bool cabin[100001]{};
for (int C, i = 0; i < M; ++i) {
cin >> C;
cabin[C] = 1;
}
int s = 0, e = 50000000;
while (s <= e) {
int m = s + e >> 1;
long cnt = 0;
bool used[100001]{};
auto go = [&](auto& go, int now, int D) -> void {
used[now] = 1;
ordered_set S;
vector<int> keep;
auto solve = [&](auto& solve, int now, int prv, int d) -> void {
if (used[now]) return;
if (cabin[now]) {
cnt += S.order_of_key(D - d + 1);
keep.push_back(d);
}
for (auto [nxt, w] : cent.org[now]) {
if (nxt == prv) continue;
solve(solve, nxt, now, d + w);
}
};
for (auto [nxt, w] : cent.org[now]) {
keep.clear();
solve(solve, nxt, now, w);
for (int it : keep) S.insert(it);
}
if (cabin[now]) {
cnt += S.order_of_key(D + 1);
}
for (int nxt : cent.adj[now]) {
if (used[nxt]) continue;
go(go, nxt, D);
}
};
go(go, root, m);
if (cnt < K) s = m + 1;
else e = m - 1;
}
cout << s;
return 0;
}
