#include <bits/stdc++.h>
#include "catdog.h"
#define DIM 100010
using namespace std;
vector <int> L[DIM],a,b;
int v[DIM],dp[DIM][3];
int n,i,q,tip,x;
void initialize(int _n, vector<int> A, vector<int> B) {
n = _n;
for (int i=0;i<n-1;i++){
L[A[i]].push_back(B[i]);
L[B[i]].push_back(A[i]);
}
}
void dfs (int nod, int tata){
int ok = 0;
for (auto vecin : L[nod])
if (vecin != tata){
ok = 1;
dfs (vecin,nod);
}
if (!ok){
if (v[nod] == 1)
dp[nod][0] = dp[nod][2] = 1;
if (v[nod] == 2)
dp[nod][0] = dp[nod][1] = 1;
} else {
if (!v[nod]){ /// nu am nimic in nod
for (auto vecin : L[nod]){
if (vecin == tata)
continue;
dp[nod][0] += min(dp[vecin][0],min(dp[vecin][1]+1,dp[vecin][2]+1));
dp[nod][1] += min (dp[vecin][1],min(dp[vecin][0],dp[vecin][2]+1));
dp[nod][2] += min (dp[vecin][2],min(dp[vecin][0],dp[vecin][1]+1));
}
} else {
if (v[nod] == 1){ /// cat
dp[nod][0] = dp[nod][2] = 1;
for (auto vecin : L[nod]){
if (vecin == tata)
continue;
int val = min (dp[vecin][0],min(dp[vecin][1],dp[vecin][2]+1));
dp[nod][0] += val;
dp[nod][1] += val;
dp[nod][2] += val;
}
} else { /// dog
dp[nod][0] = dp[nod][1] = 1;
for (auto vecin : L[nod]){
if (vecin == tata)
continue;
int val = min (dp[vecin][0],min(dp[vecin][2],dp[vecin][1]+1));
dp[nod][0] += val;
dp[nod][1] += val;
dp[nod][2] += val;
}
}
}
}
}
int cat(int x) {
v[x] = 1;
memset (dp,0,sizeof dp);
dfs (1,0);
return min (dp[1][0],min(dp[1][1],dp[1][2]));
}
int dog(int x) {
v[x] = 2;
memset (dp,0,sizeof dp);
dfs (1,0);
return min (dp[1][0],min(dp[1][1],dp[1][2]));
}
int neighbor(int x) {
v[x] = 0;
memset (dp,0,sizeof dp);
dfs (1,0);
return min (dp[1][0],min(dp[1][1],dp[1][2]));
}
/*
int main (){
ifstream cin ("date.in");
ofstream cout ("date.out");
cin>>n;
for (i=0;i<n-1;i++){
int x,y;
cin>>x>>y;
a.push_back(x);
b.push_back(y);
//cin>>a[i]>>b[i];
}
initialize(n,a,b);
cin>>q;
for (;q--;){
cin>>tip>>x;
if (tip == 1)
cout<<cat(x)<<"\n";
else {
if (tip == 2)
cout<<dog(x)<<"\n";
else cout<<neighbor(x)<<"\n";
}
}
return 0;
}
*/
