#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define fi first
#define se second
const int N = 2e5+5;
const int base = 4e3;
int n,dp[N][2],val[N];
string s;
vector<int>adj[N];
void dfs(int u, int p){
if(adj[u].size() == 1 && u != 1) dp[u][0] = dp[u][1] = val[u];
int sum = 0;
for(int v: adj[u]){
if(v != p){
dfs(v,u);
dp[u][0] = max({dp[u][0],dp[v][1]+val[u],dp[v][0]});
dp[u][1] += dp[v][1];
}
}
dp[u][1] -= val[u];
dp[u][1] = max(dp[u][1],val[u]);
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
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);
}
cin >> s;
for(int i = 0; i < n; i++) val[i+1] = s[i]-'0';
dfs(1,0);
// for(int i = 1; i <= n; i++){
// for(int j = 0; j <= 1; j++) cout << i << " " << j << " " << dp[i][j] << "\n";
// }
cout << max(dp[1][0],dp[1][1]);
}
