#include <bits/stdc++.h>
using namespace std;
const int N = 2e5;
vector<int> g[N];
string s;
int dp[2][N];
void dfs(int u, int p) {
dp[0][u] = dp[1][u] = s[u];
int sum_dp = 0, mx_dp = 0;
for (int v : g[u]) {
if (v != p) {
dfs(v, u);
dp[0][u] = max(dp[0][u], dp[0][v]);
sum_dp += dp[1][v];
mx_dp = max(mx_dp, dp[1][v]);
}
}
dp[0][u] = max({dp[0][u], sum_dp - s[u], mx_dp + s[u]});
dp[1][u] = max(dp[1][u], sum_dp - s[u]);
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
int n;
cin >> n;
for (int i = 0; i < n - 1; i++) {
int a, b;
cin >> a >> b;
g[--a].push_back(--b);
g[b].push_back(a);
}
cin >> s;
for (char &c : s) c -= '0';
dfs(0, 0);
cout << dp[0][0] << '\n';
return 0;
}
