#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define ep insert
#define endl '\n'
#define elif else if
#define pow pwr
#define sqrt sqrtt
#define int long long
#define y1 YONE
typedef unsigned long long ull;
using namespace std;
const int N=2e5+5;
int n,dp[N],ans;
vector<int> adj[N];
bool a[N];
int rec(int node,int p){
//int s=bool(p);
dp[node]=0;
for (auto u:adj[node]) if (u!=p) dp[node]+=rec(u,node);
if (adj[node].size()<=1) dp[node]+=a[node];
else dp[node]-=a[node];
return dp[node]=max(dp[node],(int)a[node]);
}
void dfs(int node,int p){
if (p) dp[p]=max(dp[p]-dp[node],(int)a[p]);
dp[node]=max(dp[node]+dp[p],(int)a[node]);
ans=max(ans,dp[node]);
for (auto u:adj[node]) if (u!=p) dfs(u,node);
return;
}
int32_t main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
cin>>n;
for (int i=1;i<n;i++){
int x,y;cin>>x>>y;
adj[x].pb(y);adj[y].pb(x);
}for (int i=1;i<=n;i++){char c;cin>>c;a[i]=c-'0';}
rec(1,0);
dfs(1,0);
cout<<ans<<endl;
return 0;
}
