#include <bits/stdc++.h>
using namespace std;
//#pragma GCC optimize("Ofast,unroll-loops")
//#pragma GCC target("avx2,popcnt,lzcnt,abm,bmi,bmi2,fma,tune=native")
using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pi3 = pair<pii, int>;
#define IOS ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define F first
#define S second
#define sz(x) x.size()
#define all(x) x.begin(), x.end()
#define pb push_back
#define minr(a, b) a = min(a, b);
#define maxr(a, b) a = max(a, b);
#define shit cout << "shit\n" << flush;
#define tl while(1&1) continue;
#define rand(l, r) uniform_int_distribution<int64_t>(l,r)(rng)
random_device device; default_random_engine rng(device());
const int Mod = 1e9 + 7; //998244353;
const int LG = 64;
const int SQ = 500;
const int Inf = 2e9 + 10;
const int maxN = 2e5 + 10;
int n;
int a[maxN];
int dp[maxN][2];
vector <int> child[maxN];
vector <int> neighb[maxN];
void dfs(int u, int p) {
int tmp = 0;
for(auto v : neighb[u]) {
if(v != p) {
dfs(v, u);
tmp += dp[v][1];
maxr(dp[u][0], dp[v][0]);
maxr(dp[u][0], dp[v][1]+a[u]);
}
}
maxr(dp[u][0], tmp-a[u]);
maxr(dp[u][1], tmp-a[u]);
maxr(dp[u][1], a[u]);
maxr(dp[u][0], a[u]);
}
int main() {
IOS;
cin >> n;
for(int i = 1; i < n; i++) {
int u, v;
cin >> u >> v;
neighb[u].pb(v);
neighb[v].pb(u);
}
for(int i = 1; i <= n; i++) {
char c;
cin >> c;
a[i] = (c == '1');
}
dfs(1, 0);
cout << dp[1][0];
}
