#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("Ofast")
#pragma GCC optimize ("unroll-loops")
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define MottoHayaku ios::sync_with_stdio(false);cin.tie(0);
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define F first
#define S second
#define pb push_back
const int N=2e5+5;
vector<int> ed[N];
int dp[N],has[N],ans=0;
void dfs(int u,int p)
{
int mx=0;
for(int v:ed[u])
{
if(v==p) continue;
dfs(v,u);
dp[u]+=dp[v];
mx=max(mx,dp[v]);
}
dp[u]-=has[u];
dp[u]=max(dp[u],has[u]);
ans=max({ans,dp[u],mx+has[u]});
}
signed main()
{
MottoHayaku
int n;
cin>>n;
string s;
rep(i,n-1)
{
int u,v;
cin>>u>>v;
ed[u].pb(v);
ed[v].pb(u);
}
cin>>s;
rep(i,n) has[i+1]=(s[i]=='1');
dfs(1,0);
cout<<ans<<"\n";
}
