#include<bits/stdc++.h>
using namespace std;
#define int long long
#define debug(x) cerr<<#x<<' '<<x<<' ';
typedef pair<int, int>PII;
typedef long long LL;
constexpr int N = 200010, mod = 1e9 + 7;
int a[N];
vector<int>v[N];
int cnt[N];
void dfs(int u,int fa)
{
    int f=0,ma=0;
    cnt[u]=0;
    for(auto c:v[u])
    {
        if(c==fa)continue;
        f++;
        dfs(c,u);
        ma=max(ma,cnt[c]);

    }
    if(f>=2)cnt[u]+=1+ma;
    else cnt[u]=ma;
}
signed main()
{
    //freopen(".in","r",stdin);freopen(".out","w",stdout);
    ios::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    int t;
    cin >> t;
    while(t--)
    {
        int n;
        cin >> n;
        for(int i=0;i<=n;i++)v[i].clear();
        for(int i = 1; i <= n; i++)
        {
            int x ;
            cin>>x;
            v[x].push_back(i);
        }
        dfs(1,0);
        cout<<cnt[1]+1-(v[1].size()>=2)<<endl;
    }

}