#include <bits/stdc++.h>
using namespace std;
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int N;
cin >> N;
vector<int> adj[N];
for (int i = 1, a, b; i < N; i++) {
cin >> a >> b;
adj[--a].push_back(--b);
adj[b].push_back(a);
}
string S;
cin >> S;
int ans = 0;
function<int(int, int)> dfs = [&](int i, int p) {
int tot = 0, mx = 0;
for (int j : adj[i]) {
if (j == p) continue;
int v = dfs(j, i);
tot += v;
mx = max(mx, v);
}
ans = max({ans, mx + S[i] - '0', tot - S[i] + '0'});
return max(S[i] - '0', tot - S[i] + '0');
};
dfs(0, 0);
cout << ans << '\n';
}
