ll n,r,u[2d5],w[2d5];
vector<ll> v[2d5];
deque<ll> q;

{
	rd(n,u(n*2-2));
	rep(i,n*2-2)v[u[i]].push_back(u[i^1]);
	rep(j,1,n+1)if(v[j].size()<2){
		q.push_back(j);
	}
	while(!q.empty()){
		ll j=q.front();
		q.pop_front();
		if(!w[j]){
			w[j]=1;
			while(!v[j].empty()){
				ll x=v[j].back();
				v[j].pop_back();
				q.push_back(x);
				if(w[x]==1){
					w[j]=2;
				}
			}
			if(w[j]==1)r+=1;
		}
	}
	wt(r);
}