#include<bits/stdc++.h>
using namespace std;
using ll = long long;
#define x first
#define y second
string s;
vector<ll> cad[200001],asd(200001,0);
vector<vector<ll>>dp;
ll dfs(ll node, ll pl, ll padre)
{
if(dp[node][pl]!=-1) return dp[node][pl];
vector<ll> temp;
ll bs=asd[node];
dp[node][pl]=asd[node];
ll asdf=0;
for(auto i:cad[node])
{
if(i==padre) continue;
temp.push_back(dfs(i,1,node));
bs=max(dfs(i,0,node),bs);
}
sort(temp.begin(),temp.end());
reverse(temp.begin(),temp.end());
ll o1=0;
for(auto i:temp)
if(i>0)o1+=i;
if(pl==0)
{
dp[node][pl]=max(o1-asd[node],dp[node][pl]);
dp[node][pl]=max(bs,dp[node][pl]);
if(temp.size()>0)
dp[node][pl]=max(temp[0]+asd[node],dp[node][pl]);
}
else
{
dp[node][pl]=max(o1-asd[node],dp[node][pl]);
}
return dp[node][pl];
}
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);cout.setf(ios::fixed);cout.precision(0);
ll n;
cin>>n;
for(int i=0; i<n-1; i++)
{
ll a,b;
cin>>a>>b;
cad[a].push_back(b);
cad[b].push_back(a);
}
cin>>s;
for(int i=0; i<n; i++)
asd[i+1]=(ll)s[i]-'0';
dp.assign(n+1,vector<ll>(3,-1));
cout<<dfs(1,0,0)<<"\n";
//for(int i=1; i<=n; i++)
//{
// cout<<i<<": "<<dp[i][0]<<" "<<dp[i][1]<<"\n";
//}
}
