/*
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2,fma,bmi,bmi2,sse4.2,popcnt,lzcnt")
*/
#include <bits/stdc++.h>
#define taskname ""
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define ll long long
#define ld long double
#define pb push_back
#define ff first
#define ss second
#define pii pair<int, int>
#define vi vector<int>
#define vii vector<pii>
using namespace std;
const int mxN = 2e5 + 5;
const int mod = 1e9 + 7;
const ll oo = 1e18;
int n;
vi G[mxN];
bool vis[mxN];
int dp[mxN][2], ans;
void dfs(int v, int p) {
int maxx = 0, cur_sum = 0;
for(int u : G[v]) {
if(u == p) continue;
dfs(u, v);
cur_sum += dp[u][1];
maxx = max(maxx, dp[u][1]);
}
dp[v][0] = max(cur_sum - vis[v], maxx + vis[v]);
dp[v][1] = max(cur_sum - vis[v], (int)vis[v]);
ans = max(ans, dp[v][0]);
}
void solve() {
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;
vis[i] = (c == '1');
}
dfs(1, 0);
cout << ans << endl;
}
signed main() {
#ifndef CDuongg
if(fopen(taskname".inp", "r"))
assert(freopen(taskname".inp", "r", stdin)), assert(freopen(taskname".out", "w", stdout));
#else
freopen("bai3.inp", "r", stdin);
freopen("bai3.out", "w", stdout);
auto start = chrono::high_resolution_clock::now();
#endif
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1; //cin >> t;
while(t--) solve();
#ifdef CDuongg
auto end = chrono::high_resolution_clock::now();
cout << "\n"; for(int i = 1; i <= 100; ++i) cout << '=';
cout << "\nExecution time: " << chrono::duration_cast<chrono::milliseconds> (end - start).count() << "[ms]" << endl;
#endif
}
