#pragma GCC optimize("Ofast")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
#define mp make_pair
#define eb emplace_back
#define pb push_back
#define e1 first
#define e2 second
#define int int_fast32_t
#define uint uint_fast64_t
#define ll int_fast64_t
#define ull uint_fast64_t
#define int16 int_fast16_t
#define uint16 uint_fast16_t
#define int32 int_fast32_t
#define uint32 uint_fast32_t
#define int64 int_fast64_t
#define uint64 uint_fast64_t
#define ld long double
#define float long double
#define size(x) (int)x.size()
#define satori int testCases; cin>>testCases; while(testCases--)
#define fastio ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define all(r) begin(r),end(r)
#define rall(r) rbegin(r),rend(r)
#define time chrono::high_resolution_clock().now().time_since_epoch().count()
#define elapsed(__begin,__end) (__end-__begin)/CLOCKS_PER_SEC
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
float pi=3.14159265358979323846;
const int MAXN=2e5+10;
int dp[MAXN],dp2[MAXN],pp[MAXN],pr[MAXN];
vector<int> g[MAXN];
string s;
void dfs(int u,int p)
{
pr[u]=p;
dp[u]=pp[u];
int sm=-pp[u];
for(auto v:g[u])
if(v!=p)
dfs(v,u),sm+=dp[v];
dp[u]=max(dp[u],sm);
}
void dfs2(int u,int p)
{
int sm=dp2[u];
for(auto v:g[u])
if(v!=p)
sm+=dp[v];
for(auto v:g[u])
if(v!=p)
dp2[v]=max(pp[u],sm-dp[v]-pp[u]),dfs2(v,u);
}
int32_t main()
{
fastio;
int n,u,v,res=0;
cin>>n;
for(int i=1;i<n;i++)
cin>>u>>v,g[u].eb(v),g[v].eb(u);
cin>>s;
for(int i=0;i<n;i++)
pp[i+1]=(int)(s[i]-'0');
dfs(1,0);
dfs2(1,0);
for(int i=1;i<=n;i++)
{
res=max(res,dp[i]+dp2[i]);
for(auto vv:g[i])
if(vv!=pr[i])
res=max(res,pp[i]+dp[vv]);
}
cout<<res<<'\n';
}
