#include <bits/stdc++.h>
#define ar array
#define all(x) x.begin(), x.end()
using namespace std;
typedef long long ll;
const int N = 2e5 + 5;
vector <int> g[N];
int a[N], dp[N], n, ans = 0;
void dfs(int x, int par) {
int sm = 0;
for (int y : g[x]) {
if (y != par) {
dfs(y, x);
ans = max(ans, dp[y] + a[x]);
sm += dp[y];
}
}
dp[x] = max(sm - a[x], dp[x]);
ans = max(ans, dp[x]);
}
int main() {
ios::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
g[u].emplace_back(v);
g[v].emplace_back(u);
}
for (int i = 1; i <= n; i++) {
char c;
cin >> c;
a[i] = dp[i] = c - '0';
}
dfs(1, 0);
cout << ans << '\n';
}
