#include <stdio.h>
#include <stdlib.h>

#include <vector>

using namespace std;

#define NMAX 100001

int T, v[NMAX], w[NMAX], p[NMAX];
vector<int> sub[NMAX];

int sort_function(const void* a, const void* b) {
	int* aa = (int*)a;
	int* bb = (int*)b;
	if (aa < bb) return 1;
	if (aa > bb) return -1;
	return 0;
}

void parc(int k) {
	int i;
	for (vector<int>::iterator it = sub[k].begin(); it != sub[k].end(); ++it) {
		parc(*it);
	}
	
	int nw = 0;
	for (vector<int>::iterator it = sub[k].begin(); it != sub[k].end(); ++it) {
		w[nw++] = *it;
	}
	
	qsort(w, nw, sizeof(int), sort_function);
	
	v[k] = 0;
	for (i = 0; i < nw; ++i) {
		//fprintf(stderr, "%d %d %d %d %d %d\n", T, i, w[i], v[w[i]], k, v[k]);
		if (v[w[i]] + i + 1 > v[k]) {
			v[k] = v[w[i]] + i + 1;
		}
	}
}

int main() {
	int n, i, j, a, b;
	freopen("zvon.in", "r", stdin);
	freopen("zvon.out", "w", stdout);
	
	scanf("%d", &T);
	while (T--) {
		scanf("%d", &n);
		for (i = 0; i < n; ++i) {
			v[i] = 0;
			p[i] = -1;
			sub[i].clear();
		}
		for (i = 0; i < n - 1; ++i) {
			scanf("%d %d", &a, &b);
			a--;
			b--;
			sub[a].push_back(b);
			p[b] = a;
		}
		
		for (i = 0; i < n; ++i) {
			if (p[i] == -1) {
				parc(i);
				printf("%d\n", v[i]);
				
				//for (j = 0; j < n; ++j) {
					//fprintf(stderr, "%d %d %d\n", T, j + 1, v[j]);
				//}
			}
		}
	}
	return 0;
}