#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#define maxN 100002
using namespace std;
int t, n, i, j, sol, w[maxN];
vector < int > V[maxN];
void solve();
void write();
int cmp(const int a, const int b)
{
    return w[a] > w[b];
}
void read()
{
    int a, b;
    freopen("zvon.in", "r", stdin);
    freopen("zvon.out", "w", stdout);
    scanf("%d", &t);
    while (t --)
    {
        scanf("%d", &n);
        sol = 0;
        memset(w, 0, sizeof(w));
        for (i = 1; i < n; ++ i)
        {
            scanf("%d %d", &a, &b);
            V[a].push_back(b);
        }
        solve();
        write();
    }
}
void dfs(int x)
{
    int i, l = V[x].size(), node;
    for (i = 0; i < l; ++ i)
        dfs(V[x][i]);
    sort(V[x].begin(), V[x].end(), cmp);
    for (i = 0; i < l; ++ i)
        w[x] = max(w[x], w[V[x][i]] + i + 1);
}
void solve()
{
    int i;
    dfs(1);
    for (i = 1; i <= n; ++ i)
        V[i].clear();
    sol = w[1];
}
void write()
{
    printf("%d\n", sol);
}
int main()
{
    read();
    return 0;
}