#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using ull = unsigned long long;
const ll base = 37;//进制
const ll mod = 998244353;//质数
const int inf = 1e9+5;
const int maxn = 5e6+5;
const ll linf = 1e18+5ll;
int main()
{
    cin.tie(NULL);
    cout.tie(NULL);
    ios::sync_with_stdio(false);
    int t;
    cin>>t;
    while(t--)
    {
        int n;
        cin>>n;
        vector<vector<int> >g(n+1);
        for(int i = 2;i<=n;i++)
        {
            int x;
            cin>>x;
            g[x].push_back(i);
        }
        vector<int>dp(n+1,0);
        vector<int>dps(n+1,0);
        function<void(int)>dfs = [&](int u){
            dp[u] = 1;
            for(auto v:g[u])
            {
                dfs(v);
                dp[u] = max(dp[u],dp[v]+1);
            }
            dps[dp[u]] += 1;
        };
        int ans = n;
        dfs(1);
        for(int i = 1;i<=n;i++)
        {
            ans = min(ans,i-1+dps[i]);
        }
        cout<<ans<<'\n';
    }
    return 0;
}