1 #include <iostream>
2 #include <stdio.h>
3 #include <math.h>
4 #include <string.h>
5 #include <stdlib.h>
6 #include <string>
7 #include <vector>
8 #include <set>
9 #include <map>
10 #include <queue>
11 #include <algorithm>
12 #include <sstream>
13 #include <stack>
14 using namespace std;
15 #define rep(i,a,n) for (int i=a;i<n;i++)
16 #define per(i,a,n) for (int i=n-1;i>=a;i--)
17 #define pb push_back
18 #define mp make_pair
19 #define all(x) (x).begin(),(x).end()
20 #define fi first
21 #define se second
22 #define SZ(x) ((int)(x).size())
23 #define FO freopen("in.txt", "r", stdin);
24 #define lowbit(x) (x&-x)
25 #define mem(a,b) memset(a, b, sizeof(a));
26 typedef vector<int> VI;
27 typedef long long ll;
28 typedef pair<int,int> PII;
29 const ll mod=1000000007;
30 const int inf = 0x3f3f3f3f;
31 ll powmod(ll a,ll b) {ll res=1;a%=mod;for(;b;b>>=1){if(b&1)res=res*a%mod;a=a*a%mod;}return res;}
32 ll gcd(ll a,ll b) { return b?gcd(b,a%b):a;}
33 //head
34
35 const int maxn = 500 + 7;
36 int d[maxn];
37 bool vis[maxn];
38 int _, n, m;
39 char ss[100 * maxn];//注意范围
40 struct node{
41 int v;
42 int dis;
43 node(){}
44 node(int _v, int _dis):v(_v), dis(_dis){}
45 };
46
47 vector<node> G[maxn];
48 void dijkstra(int st) {//基操
49 fill(d, d+maxn, inf);
50 mem(vis, false);
51 d[st] = 0;
52 rep(i, 1, n+1) {
53 int minn = inf, u = -1;
54 rep(j, 1, n+1) {
55 if(d[j] < minn && !vis[j]) {
56 minn = d[j];
57 u = j;
58 }
59 }
60 if(u == -1) return;
61 vis[u] = true;
62 rep(j, 0, SZ(G[u])) {
63 int v = G[u][j].v;
64 if(d[u] + G[u][j].dis < d[v] && !vis[v]) {
65 d[v] = d[u] + G[u][j].dis;
66 }
67 }
68 }
69 }
70
71 int main() {
72 for(scanf("%d", &_);_;_--) {
73 scanf("%d%d", &m, &n);
74 mem(G, 0);
75 getchar();
76 while(m--) {
77 gets(ss);
78 int len = strlen(ss);
79 VI temp;
80 int zhi = 0;
81 rep(i, 0, len) {//把数据放入temp
82 if(ss[i] == ' ' || i == len - 1) {
83 if(i == len - 1)
84 zhi = zhi * 10 + ss[i] - '0';
85 temp.pb(zhi);
86 zhi = 0;
87 } else zhi = zhi * 10 + ss[i] - '0';
88 }
89 rep(i, 0, SZ(temp)) {//存边
90 rep(j, i+1, SZ(temp)) {
91 G[temp[i]].pb(node(temp[j], 1));
92 }
93 }
94 }
95 dijkstra(1);
96 if(d[n] == inf)
97 printf("NO\n");
98 else
99 printf("%d\n", d[n]-1);
100 }
101 }