// ~~ icebear ~~
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
template<class T>
bool minimize(T &a, const T &b) {
if (a > b) return a = b, true;
return false;
}
template<class T>
bool maximize(T &a, const T &b) {
if (a < b) return a = b, true;
return false;
}
#define FOR(i,a,b) for(int i=(a); i<=(b); ++i)
#define FORR(i,a,b) for(int i=(a); i>=(b); --i)
#define REP(i, n) for(int i=0; i<(n); ++i)
#define RED(i, n) for(int i=(n)-1; i>=0; --i)
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define task "icebear"
const int MOD = 1e9 + 7;
const int inf = 1e9 + 27092008;
const ll INF = 1e18 + 27092008;
const int N = 1e5 + 5;
int n, q;
vector<int> G[N];
int f[N][3], state[N];
void initialize(int N, vector<int> A, vector<int> B) {
n = N;
FOR(i, 0, N - 2) {
G[A[i]].pb(B[i]);
G[B[i]].pb(A[i]);
}
}
void dfs(int u, int par) {
if (state[u] == 0) f[u][0] = f[u][1] = f[u][2] = 0;
else f[u][state[u]] = 0;
for(int v : G[u]) if (v != par) {
dfs(v, u);
f[u][0] = min(inf, f[u][0] + min({f[v][0], f[v][1] + 1, f[v][2] + 1}));
f[u][1] = min(inf, f[u][1] + min({f[v][1], f[v][0], f[v][2] + 1}));
f[u][2] = min(inf, f[u][2] + min({f[v][2], f[v][0], f[v][1] + 1}));
}
}
int cat(int v) {
state[v] = 1;
memset(f, 0x3f, sizeof f);
dfs(1, -1);
return min({f[1][0], f[1][1], f[1][2]});
}
int dog(int v) {
state[v] = 2;
memset(f, 0x3f, sizeof f);
dfs(1, -1);
return min({f[1][0], f[1][1], f[1][2]});
}
int neighbor(int v) {
state[v] = 0;
memset(f, 0x3f, sizeof f);
dfs(1, -1);
return min({f[1][0], f[1][1], f[1][2]});
}
//void init(void) {
// initialize(n, A, B);
//}
//
//void process(void) {
// cin >> q;
// while(q--) {
// int t, v;
// cin >> t >> v;
// if (t == 1) cat(v);
// else if (t == 2) dog(v);
// else neighbor(v);
// memset(f, 0x3f, sizeof f);
// dfs(1, -1);
// cout << min({f[1][0], f[1][1], f[1][2]}) << '\n';
// }
//}
//
//int main() {
// ios_base::sync_with_stdio(0);
// cin.tie(0); cout.tie(0);
// if (fopen(task".inp", "r")) {
// freopen(task".inp", "r", stdin);
// freopen(task".out", "w", stdout);
// }
// int tc = 1;
//// cin >> tc;
// while(tc--) {
// init();
// process();
// }
// return 0;
//}
