#include <bits/stdc++.h>
#define rep(x, l, r) for(int x = l; x <= r; x++)
#define repd(x, r, l) for(int x = r; x >= l; x--)
#define pb push_back
#define SZ(x) ((int)x.size())
using namespace std;

const int INF = 0x3f3f3f3f;
const int MAXN = 1e6 + 5;
int n, cnt;
int head[MAXN], nxt[MAXN], to[MAXN];
int son[MAXN], sum[MAXN], s[MAXN], dep[MAXN];
vector<int> ve[MAXN];

struct node{
    int num, id;
} a[MAXN];

bool cmp(node a, node b){
    return a.num > b.num;
}

void addedge(int u, int v){
    nxt[cnt] = head[u];
    head[u] = cnt;
    to[cnt] = v;
    cnt++;
}

void dfs1(int u){
    son[u] = -1; sum[u] = 1;
    for(int e = head[u]; e != -1; e = nxt[e]){
        int v = to[e];
        dep[v] = dep[u] + 1;
        dfs1(v);
        sum[u] = max(sum[u], sum[v] + 1);
        if(son[u] == -1 || sum[v] > sum[son[u]]) son[u] = v;
    }
}

void dfs2(int u, int t){
    ve[t].pb(u);
    if(son[u] == -1) return;
    dfs2(son[u], t);
    for(int e = head[u]; e != -1; e = nxt[e]){
        int v = to[e];
        if(v == son[u]) continue;
        dfs2(v, v);
    }
}

int main(){
    int t;
    scanf("%d", &t);
    while(t--){
        scanf("%d", &n);
        cnt = 0;
        rep(i, 1, n){
            head[i] = -1;
            s[i] = 0;
            dep[i] = 0;
            ve[i].clear();
        }
        rep(i, 2, n){
            int x;
            scanf("%d", &x);
            addedge(x, i);
        }
        dep[1] = 0;
        dfs1(1);
        dfs2(1, 1);
        rep(i, 1, n){
            a[i] = (node){SZ(ve[i]), i};
        }
        sort(a + 1, a + n + 1, cmp);
        int ans = n;
        rep(i, 1, n){
            ans = min(ans, i - 1 + a[i].num);
        }
        printf("%d\n", ans);
    }
    return 0;
}