#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pii pair<int, int>
#define ff first
#define ss second
#define pb push_back
#define rep(i, a, b) for (int i = (int)a; i <= (int)b; ++i)
#define rep1(i, a, b) for (int i = (int)a; i >= (int)b; --i)
#define all(x) x.begin(), x.end()
const int N = 2e5 + 5;
int dp[N], sig[N];
vector<int> g[N];
int ans = 0;
void dfs(int u, int p) {
int sum = 0;
for (int v : g[u]) {
if (v == p) continue;
dfs(v, u);
sum += dp[v];
ans = max(ans, dp[v] + sig[u]);
}
dp[u] = max(sig[u], sum - sig[u]);
ans = max(ans, dp[u]);
}
void solve() {
int n; cin >> n;
for (int i = 1; i < n; ++i) {
int u, v; cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
string s; cin >> s;
rep(i, 1, n) sig[i] = s[i - 1] - '0';
dfs(1, 0);
cout << ans;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
solve();
}
