#include <bits/stdc++.h>
using namespace std;
template<typename T>
struct DynamicSegmentTree {
struct Node {
int l, r, v;
Node(int l = -1, int r = -1, int v = 0): l(l), r(r), v(v) {}
};
vector<Node> tree;
int SZ;
T id;
DynamicSegmentTree(int sz, const T& id) {
SZ = sz;
this->id = id;
tree.emplace_back(-1, -1, id);
}
void update(int idx, const T& val) {
update(idx, val, 0, 0, SZ - 1);
}
T query(int L, int R) {
return query(L, R, 0, 0, SZ - 1);
}
private:
void update(int idx, const T& val, int node, int s, int e) {
if (e < idx || idx < s) return;
if (s == e) {
tree[node].v += val;
return;
}
int m = s + e >> 1;
if (tree[node].l == -1) {
tree[node].l = tree.size();
tree.emplace_back(-1, -1, id);
}
if (tree[node].r == -1) {
tree[node].r = tree.size();
tree.emplace_back(-1, -1, id);
}
update(idx, val, tree[node].l, s, m);
update(idx, val, tree[node].r, m + 1, e);
tree[node].v = tree[tree[node].l].v + tree[tree[node].r].v;
}
T query(int L, int R, int node, int s, int e) {
if (node == -1 || e < L || R < s) return id;
if (L <= s && e <= R) return tree[node].v;
int m = s + e >> 1;
return combine(query(L, R, tree[node].l, s, m), query(L, R, tree[node].r, m + 1, e));
}
T combine(const T& a, const T& b) {
return a + b;
}
};
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;
}
long cnt;
bool used[100001];
auto go = [&](auto& go, int now, int D) -> void {
used[now] = 1;
DynamicSegmentTree<int> seg(25000001, 0);
vector<int> keep;
auto solve = [&](auto& solve, int now, int prv, int d) -> void {
if (used[now]) return;
if (cabin[now]) {
cnt += seg.query(0, D - d);
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) seg.update(it, 1);
}
if (cabin[now]) {
cnt += seg.query(0, D);
}
for (int nxt : cent.adj[now]) {
if (used[nxt]) continue;
go(go, nxt, D);
}
};
int s = 0, e = 25000000;
while (s <= e) {
int m = s + e >> 1;
cnt = 0;
memset(used, 0, N + 1);
go(go, root, m);
if (cnt < K) s = m + 1;
else e = m - 1;
}
cout << s;
return 0;
}
