/* -*- coding: utf-8 -*- * * 763.cc: No.763 Noelちゃんと木遊び - yukicoder */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; /* constant */ const int MAX_N = 100000; /* typedef */ typedef vector vi; typedef queue qi; /* global variables */ vi nbrs[MAX_N]; int ps[MAX_N], cs[MAX_N], dp[MAX_N][2]; /* subroutines */ /* main */ int main() { int n; scanf("%d", &n); for (int i = 1; i < n; i++) { int u, v; scanf("%d%d", &u, &v); u--, v--; nbrs[u].push_back(v); nbrs[v].push_back(u); } ps[0] = -1; qi q; q.push(0); while (! q.empty()) { int u = q.front(); q.pop(); int &up = ps[u]; vi &nbru = nbrs[u]; for (vi::iterator vit = nbru.begin(); vit != nbru.end(); vit++) { int &v = *vit; if (v != up) { cs[u]++; ps[v] = u; q.push(v); } } } for (int i = 0; i < n; i++) if (cs[i] == 0) q.push(i); while (! q.empty()) { int u = q.front(); q.pop(); dp[u][1]++; int &up = ps[u]; if (up >= 0) { dp[up][0] += max(dp[u][0], dp[u][1]); dp[up][1] += max(dp[u][0], dp[u][1] - 1); if (--cs[up] == 0) q.push(up); } } printf("%d\n", max(dp[0][0], dp[0][1])); return 0; }