//#pragma GCC optimize("Ofast")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma")
//#pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
#define ll long long
#define int long long
const int nmax = 2e5 + 5, N = 1e5;
const ll oo = 1e18;
const int lg = 19, M = 2, mod = 1e6;
#define pii pair<ll, ll>
#define fi first
#define se second
#define debug(a, n) for(int i = 1; i <= n; ++i) cout << a[i] << ' '; cout << "\n";
#define endl "\n"
#define task "code"
using namespace std;
int n;
vector<int> adj[nmax];
int a[nmax], dp[nmax], ans = 0;
void dfs(int u, int p){
bool ok = 0, ok2 = 0;
for(auto v : adj[u]){
if(v == p) continue;
dfs(v, u);
dp[u] += dp[v];
ans = max(ans, dp[v] + a[u]);
}
dp[u] -= a[u];
dp[u] = max(dp[u], a[u]);
ans = max(ans, dp[u]);
}
main(){
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
//// freopen(task".inp", "r", stdin);
// freopen(task".out", "w", stdout);
cin >> n;
for(int i = 1; i < n; ++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 x;
cin >> x;
a[i] = (x == '1');
}
dfs(1, -1);
// debug(a, n);
cout << ans;
}
/*
4 3
0 1 1
1 1 0
0 0 0
0 0 0
5
2 2
1 3
3 2
4 3
1 3
*/
