// cre: Nguyen Ngoc Hung - Train VOI 2024
#include<bits/stdc++.h>
using namespace std;
#define __nnhzzz__ signed main()
#define BIT(i,j) ((i>>j)&1LL)
#define MASK(i) (1LL<<i)
#define ALL(x) (x).begin(),(x).end()
#define SZ(x) (int)(x).size()
#define gcd __gcd
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define ld long double
#define vi vector<int>
#define vvi vector<vi>
#define vvvi vector<vvi>
#define pii pair<int,int>
#define vpii vector<pii>
#define REP(i,a,b) for(int i = (a); i<=(b); ++i)
#define REPD(i,a,b) for(int i = (a); i>=(b); --i)
#define REPDIS(i,a,b,c) for(int i = (a); i<=(b); i+=c)
//-------------------------------------------------------------//
const int oo = 1e9,LOG = 20,MAXN = 2e5+7,N = 1e2+3;
const int MOD = 1e9+7,MOD1 = 1e9+207,MOD2 = 1e9+407,MOD3 = 998244353;
//-------------------------------------------------------------//
template<typename T> bool mini(T &a, const T &b){if(a>b){a=b;return true;}return false;}
template<typename T> bool maxi(T &a, const T &b){if(a<b){a=b;return true;}return false;}
/*
----------------------------------------------------------------
END OF TEMPLATE
----------------------------------------------------------------
Nguyen Ngoc Hung - nnhzzz
Training for VOI24 gold medal
----------------------------------------------------------------
*/
int dp[MAXN],x[MAXN];
vi adj[MAXN];
int res = 0;
int dfs(int u, int par){
int ma = 0;
for(auto &v:adj[u]){
if(v==par) continue;
dp[u] += dfs(v,u);
maxi(ma,dp[v]);
}
dp[u] = max(dp[u]-x[u],x[u]);
maxi(res,max(dp[u],ma+x[u]));
return dp[u];
}
void solve(){
int n; cin >> n;
REP(i,2,n){
int u,v; cin >> u >> v;
adj[u].push_back(v);
adj[v].push_back(u);
}
string s; cin >> s;
REP(i,1,n) x[i] = s[i-1]-'0';
dfs(1,0);
cout << res;
}
__nnhzzz__{
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define name "test"
if(fopen(name".inp","r")){
freopen(name".inp","r",stdin);
freopen(name".out","w",stdout);
}
#define name1 "nnhzzz"
if(fopen(name1".inp","r")){
freopen(name1".inp","r",stdin);
freopen(name1".out","w",stdout);
}
int test = 1;
while(test--){
solve();
}
cerr << "\nTime elapsed: " << 1000*clock()/CLOCKS_PER_SEC << "ms\n";
return 0;
}
