#include <iostream>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <iomanip>
using namespace std;

const int N = 2e5 + 5, inf = 1e9;
#define pb push_back
#define mp make_pair
#define ll long long
#define ff first
#define ss second
#define all(a) a.begin(),a.end()
#define sz(x) (int)x.size()
typedef vector<int> vi;
typedef pair<int,int> ii;
typedef vector<ii> vii;

vi g[N];
bool ok = true;

void dfs(int u, int p){
    int cnt = 0;
    for(int v : g[u]){
        if(v == p)continue;
        cnt++;
    }
    ok &= (cnt <= 1);
}
void solve(){
	int n;
	cin >> n;
	
    int root = -1;
    for(int i = 0; i <= n; i++){
        g[i].clear();
    }
	for(int i = 1; i <= n; i++){
		int x; cin >> x;
        if(x == 0){
            root = i;
            continue;
        }
        g[i].pb(x);
        g[x].pb(i);
	}
    ok = true;
    dfs(1, 0);
    
    if(ok){
        cout << 1 << '\n';
    } else {
        cout << 2 << '\n';
    }
}

int main(){
	ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	int t = 1;
	cin >> t;
	while(t--){
		solve();
	}
	return 0;
}