#include <bits/stdc++.h>
#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())
using namespace std;
template<typename U, typename V> bool maxi(U &a, V b) {
if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
if (a > b or a == -1) { a = b; return 1; } return 0;
}
const int N = (int)1e5 + 9;
const int mod = (int)1e9 + 7;
int n, m;
int mx[N], a[5][N], L[N], R[N];
vector<int> g[N];
void dfs(int u, int p) {
mx[u] = R[u];
for(int v : g[u]) if (v != p) {
dfs(v, u);
mx[u] = max(mx[u], mx[v]);
}
}
int solve(int N, int M, vector<int> F, vector<vector<int>> S) {
n = N, m = M;
FOR(i, 0, n - 1) {
g[i].clear();
L[i] = n;
R[i] = mx[i] = 0;
}
for(int i = 0; i < m; ++i) {
for(int j = 0; j < n - 1; ++j)
a[i][j] = S[i][j];
}
for(int i = 0; i < m; ++i) {
for(int j = 0; j < n - 1; ++j) {
maxi(R[a[i][j]], j);
mini(L[a[i][j]], j);
}
}
FOR(i, 1, n - 1) {
g[F[i]].push_back(i);
}
dfs(0, -1);
vector<int> dp(n + 1, -1);
for(int i = 0; i < n - 1; ++i) {
int r = 0;
int e = n, b = 0;
for(int j = i; j >= 0; --j) {
r = max(r, mx[a[0][j]]);
for(int t = 0; t < m; ++t) {
mini(e, L[a[t][j]]);
maxi(b, R[a[t][j]]);
}
if (r > i) break ;
if (j <= e and b <= i and r <= i) {
if (j == 0 or dp[j - 1] != -1) {
maxi(dp[i], (j > 0 ? dp[j - 1] : 0) + 1);
}
}
}
}
return dp[n - 2];
}
#ifdef LOCAL
void taskcase() {
int N, M;
assert(2 == scanf("%d%d", &N, &M));
std::vector<int> F(N);
F[0] = -1;
for (int i = 1; i < N; ++i)
assert(1 == scanf("%d", &F[i]));
std::vector<std::vector<int>> S(M, std::vector<int>(N - 1));
for (int i = 0; i < M; ++i)
for (int j = 0; j < N - 1; ++j)
assert(1 == scanf("%d", &S[i][j]));
printf("%d\n", solve(N, M, F, S));
}
int main() {
ios::sync_with_stdio(0); cin.tie(0);
freopen("main.inp", "r", stdin);
freopen("main.out", "w", stdout);
int T;
assert(1 == scanf("%d", &T));
while(T--) taskcase();
return 0;
}
#endif
