#include <bits/stdc++.h>
using namespace std;
const int MAXN = 4e5 + 5;
int n, ans;
int c[MAXN], dp[MAXN];
string s;
vector <int> Adj[MAXN];
void DFS(int node, int p = -1)
{
dp[node] = c[node];
int sum = 0;
for(auto x : Adj[node])
{
if(x == p)
{
continue;
}
DFS(x, node);
sum += dp[x];
}
dp[node] = max(dp[node], sum - c[node]);
}
void DFS2(int node, int p = -1, int curdp = 0)
{
int sum = 0;
vector <int> VV;
for(auto x : Adj[node])
{
if(x == p)
{
VV.push_back(curdp);
sum += curdp;
}
else
{
VV.push_back(dp[x]);
sum += dp[x];
}
}
ans = max(ans, c[node]);
ans = max(ans, sum - c[node]);
for(int i = 0; i < (int)Adj[node].size(); i++)
{
int x = Adj[node][i];
if(x == p)
{
continue;
}
DFS2(x, node, max(c[node], sum - c[node] - VV[i]));
}
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
cin >> n;
for(int i = 1; i < n; i++)
{
int u, v;
cin >> u >> v;
Adj[u].push_back(n + i);
Adj[n + i].push_back(u);
Adj[v].push_back(n + i);
Adj[n + i].push_back(v);
}
cin >> s;
for(int i = 1; i <= n; i++)
{
c[i] = s[i - 1] - '0';
}
DFS(1);
ans = dp[1];
DFS2(1);
cout << ans << '\n';
}
