#include <bits/stdc++.h>
using namespace std;
using ll = long long int;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef pair<ll,ll> ii;
typedef vector<ii> vii;
#define F first
#define S second
ll min(ll x, ll y){
return ((x < y) ? x : y);
}
ll max(ll x, ll y){
return ((x > y) ? x : y);
}
class Tree {
private:
ll n;
vi memo,p,b,sz;
vvi adjList;
void DFS (ll v){
//cout << v << endl;
sz[v] += b[v];
for (auto u: adjList[v]){
if (u == p[v]) continue;
p[u] = v;
DFS(u);
sz[v] += sz[u];
}
}
ll dp(ll v){
if (memo[v] != -1) return memo[v];
memo[v] = -b[v];
for (auto u: adjList[v]){
//cout << v << " -> " << u << endl;
if (u == p[v]) continue;
memo[v] += dp(u);
}
memo[v] = max(memo[v],b[v]);
//cout << v << ": " << memo[v] << endl;
return memo[v];
}
public:
Tree(ll _n){
n = _n;
p.assign(n,-1);
memo.assign(n,-1);
adjList.resize(n);
sz.assign(n,0);
}
void add_edge(ll u, ll v){
adjList[u].push_back(v);
adjList[v].push_back(u);
}
void set_b(vi _b){
b.resize(n);
b = _b;
}
ll solve(){
DFS(0);
dp(0);
ll res = 0;
/*
cout << "sz: \n";
for (auto i: sz) cout << i << " ";
cout << endl;
*/
for (ll i = 0; n > i; i++){
ll cur = memo[i];
if (sz[0] != sz[i]) cur++;
//cout << i << ": " << cur << endl;
res = max(res,cur);
}
return res;
}
};
int main(){
ll n; cin >> n;
Tree tree(n);
for (ll i = 0; n-1 > i; i++){
ll u,v;
cin >> u >> v;
u--; v--;
tree.add_edge(u,v);
}
vi b;
b.resize(n);
for (ll i = 0; n > i; i++){
char c; cin >> c;
b[i] = (c == '1');
}
tree.set_b(b);
cout << tree.solve() << '\n';
}
