#include <bits/stdc++.h> using namespace std; #define int long long class tree { int n; vector <int> dp; vector <vector <int>> gr; string is; int ans = 0; void dfs(int num, int last) { int counter = 0; int mx = 0; for (int next : gr[num]) { if (next != last) { dfs(next, num); if (dp[next] > 0) { ++counter; } mx = max(mx, dp[next]); dp[num] += dp[next]; } } if (is[num] == '1') { ans = max(ans, mx + 1); if (counter < 2) { ans = max(ans, dp[num] + 1); } dp[num] = max(dp[num] - 1, 1LL); } ans = max(ans, dp[num]); } public: void init() { cin >> n; dp.resize(n, 0); gr.resize(n); for (int i = 0; i < n - 1; ++i) { int a, b; cin >> a >> b; --a; --b; gr[a].push_back(b); gr[b].push_back(a); } cin >> is; } void get_ans() { dfs(0, 0); cout << ans << '\n'; } }; void solve() { tree now; now.init(); now.get_ans(); } signed main() { cin.tie(0); ios::sync_with_stdio(false); solve(); }