ll n,r,u[2d5];
vector<ll>v[2d5];
ll f(ll j,ll p){
	ll a=1;
	for(ll x:v[j])a&=x-p?f(x,j):1;
	r+=a;
	return!a;
}

{
	rd(n,u(n*2-2));
	rep(i,n*2-2)v[u[i]].push_back(u[i^1]);
	f(1,1);
	wt(r);
}