#include<bits/stdc++.h>
using namespace std;
#define IOS ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);


using ll = long long;

#define irep(i,l,r) for(int i = l; i <= r; ++i)
#define drep(i,r,l) for(int i = r; i >= l; -- i)
#define int ll
#define endl "\n"
#define no cout << "NO" << endl
#define yes cout << "YES" << endl
#define pb push_back
#define mkp make_pair
#define fi first
#define se second
#define ary(i) array<ll,(i)>
#define all(x) x.begin(),x.end()
const int maxn=2e5+7;
const int itinf=1e9+7;
const int mod=998244353;

inline int read(){
	int x;
	cin >> x;
	return x;
}

void solve(){
	int n = read();
	vector<int>deg(n), fa(n);
	for(int i = 1; i < n; ++ i){
		int v = read() - 1;
		fa[i] = v;
		deg[v] ++;
	}
	stack<int> S, T;
	irep(i, 0, n - 1){
		if(deg[i] == 0){
			S.push(i);
		}
	}
	ll ans = itinf;
	int step = 0;
	while(1){
		ans = min(ans, (ll)S.size() + step);
		if(S.empty())break;
		while(S.size()){
			int x = S.top();
			-- deg[fa[x]];
			if(deg[fa[x]] == 0){
				T.push(fa[x]);
			}
			S.pop();
		}	
		++ step;
		swap(S, T);
	}
	cout << ans << endl;
	
	/*
//	int ans = itinf;
	vector<vector<int>>t(n);
	irep(i,1,n - 1){
		int u = read() - 1 , v = i;
		t[u].push_back(v);
		t[v].push_back(u);
	}
	int maxd = 0;
	vector<int>dp(n), dcnt(n), le(n);
	auto dfs = [&](auto self, int x) -> void{
		bool isl = 1;
		maxd = max(maxd, dp[x]);
		dcnt[dp[x]] ++;
		for(int y : t[x]){
			if(dp[y] == 0 && y != 0){
				dp[y] = dp[x] + 1;
				self(self, y);
				isl = 0;
			}
		}
		if(isl == 1){
			le[dp[x]] ++;
		}
	};
	
	dfs(dfs,0);

	drep(i,n - 2, 0){
		le[i] += le[i + 1];
	}
	int ans = min(le[0], maxd + 1);
	drep(i, maxd, 0){
		ans = min(ans, i + 1 + le[i + 1]);
	}
	
	cout << ans << endl;
	*/
}

#undef int



int main()
{
    IOS
    int T;
    cin>>T;
    // n=1;
    while(T--){
        solve();
    }

}