#include using namespace std; #define fst(t) std::get<0>(t) #define snd(t) std::get<1>(t) #define thd(t) std::get<2>(t) #define unless(p) if(!(p)) #define until(p) while(!(p)) using ll = long long; using P = std::tuple; const int dx[8] = {-1, 1, 0, 0, -1, -1, 1, 1}, dy[8] = {0, 0, -1, 1, -1, 1, -1, 1}; int N; std::vector G[100100]; int dp[100100][2]; int rec(int v, int p, int f){ if(v > N){ return 0; } // v を残す int n = !f; for(int w : G[v]){ if(w == p){ continue; } n += rec(w, v, 1); } // v を取り去る int m = 0; for(int w : G[v]){ if(w == p){ continue; } m += rec(w, v, 0); } int res = std::max(n, m); return dp[v][f] = res; } int main(){ std::cin.tie(nullptr); std::ios::sync_with_stdio(false); std::cin >> N; for(int i=0;i> u >> v; G[u].emplace_back(v); G[v].emplace_back(u); } memset(dp, -1, sizeof(dp)); int res = rec(1, -1, 0); std::cout << res << std::endl; }