#include //#include using namespace std; //using namespace atcoder; //using mint = modint998244353; //const int mod = 998244353; //using mint = modint1000000007; //const int mod = 1000000007; //const int INF = 1e9; //const long long LINF = 1e18; #define rep(i, n) for (int i = 0; i < (n); ++i) #define rep2(i,l,r)for(int i=(l);i<(r);++i) #define rrep(i, n) for (int i = (n-1); i >= 0; --i) #define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i) #define all(x) (x).begin(),(x).end() #define allR(x) (x).rbegin(),(x).rend() #define P pair template inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; } #include #include struct ReRooting { struct Edge { int to; Edge(int _to) :to(_to) {} }; struct Data { int val0 = 0; int val1 = 0; Data(int val0 = 0, int val1 = 0) :val0(val0), val1(val1) {} }; std::vector>g; std::vectordp; std::vectorans; int sz; ReRooting(int _sz) :sz(_sz) { g.resize(sz); dp.reserve(sz); ans.resize(sz); } void ReadGraph() { for (int i = 0; i < sz - 1; ++i) { int a, b; std::cin >> a >> b; a--; b--; g[a].push_back(b); g[b].push_back(a); } } Data merge(const Data &lh, const Data &rh) { Data ret = lh; ret.val0 += max(rh.val0, rh.val1); ret.val1 += rh.val0; return ret; } Data mergeR(const Data &lh, const Data &rh) { Data ret = lh; ret.val0 -= max(rh.val0, rh.val1); ret.val1 -= rh.val0; return ret; } void dfs(int v, int p = -1) { Data val(0, 1); for (auto e : g[v]) { if (p == e.to)continue; dfs(e.to, v); val = merge(val, dp[e.to]); } dp[v] = val; } void dfsR(int v, int p = -1) { ans[v] = dp[v]; if (-1 != p)ans[v] = merge(ans[v], dp[p]); for (auto e : g[v]) { if (p == e.to)continue; dp[v] = mergeR(ans[v], dp[e.to]); dfsR(e.to, v); } } void output() { int val = sz; rep(i, sz)chmin(val, ans[i].val1); cout << val << endl; } void solve() { ReadGraph(); dfs(0); dfsR(0); output(); } }; int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int n; cin >> n; ReRooting reroot(n); reroot.solve(); return 0; }