1 #include<iostream> 2 #include<cstdio> 3 #include<algorithm> 4 #include<cstring> 5 using namespace std; 6 const int maxn=1007; 7 const int INF=0x7f7f7f7f; 8 int n,ans; 9 int fa[maxn],a[maxn],dis[maxn],dep[maxn]; 10 bool cmp(int x,int y){ 11 return dep[x]>dep[y]; 12 } 13 int main(){ 14 memset(dis,INF,sizeof(dis)); 15 cin>>n;a[1]=1;fa[1]=0; 16 for(int i=2;i<=n;i++){ 17 cin>>fa[i];a[i]=i; 18 dep[i]=dep[fa[i]]+1; 19 } 20 sort(a+1,a+n+1,cmp); 21 for(int i=1;i<=n;i++){ 22 int u=a[i];int v=fa[u];int w=fa[v]; 23 dis[u]=min(dis[u],min(dis[v]+1,dis[w]+2)); 24 if(dis[u]>2){ 25 dis[w]=0;ans++; 26 dis[fa[w]]=min(dis[fa[w]],1); 27 dis[fa[fa[w]]]=min(dis[fa[fa[w]]],2); 28 } 29 } 30 cout<<ans<<endl; 31 return 0; 32 }