/* In the name of God, aka Allah */
#include<bits/stdc++.h>
using namespace std;
#define F first
#define S second
#define endl '\n'
#define mk make_pair
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
const int N = 2e5 + 50;
int n, dp[N][2];
int mark[N];
vector<int> adj[N];
void dfs(int u, int p=0) {
for (int v:adj[u]) {
if (v == p) continue;
dfs(v, u);
dp[u][0] = max(dp[u][0], max(dp[v][0], dp[v][1]+mark[u]));
dp[u][1] += dp[v][1];
}
dp[u][1] = max(dp[u][1]-mark[u], mark[u]);
dp[u][0] = max(dp[u][0], dp[u][1]);
}
void solve() {
cin >> n;
for (int i = 1; i <= n-1; i++) {
int u, v;
cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
for (int i = 1; i <= n; i++) {
char c;
cin >> c;
mark[i] = c-'0';
}
dfs(1);
cout << dp[1][0] << endl;
}
int main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
solve();
return 0;
}
