1 #include<iostream>
  2 #include<cstdio>
  3 using    namespace    std;
  4 
  5 const    int    HEAD = 0;
  6 const    int    N = 1005;
  7 int    MAP[N][N];
  8 int    U[N * N],D[N * N],L[N * N],R[N * N],H[N * N],C[N * N],ANS[N * N];
  9 
 10 void    ini(int col);
 11 bool    dancing(int k);
 12 void    output(void);
 13 void    remove(int c);
 14 void    resume(int c);
 15 int    main(void)
 16 {
 17     int    n,m,num,col;
 18     int    count,front,first;
 19 
 20     while(cin >> n >> m)
 21     {
 22         ini(m);
 23 
 24         count = m + 1;
 25         for(int i = 1;i <= n;i ++)
 26         {
 27             cin >> num;
 28             front = first = count;
 29             while(num --)
 30             {
 31                 cin >> col;
 32 
 33                 U[count] = U[col];
 34                 D[count] = col;
 35                 L[count] = front;
 36                 R[count] = first;
 37 
 38                 D[U[col]] = count;
 39                 U[col] = count;
 40                 R[front] = count;
 41 
 42                 H[count] = i;
 43                 C[count] = col;
 44                 front = count;
 45                 count ++;
 46             }
 47             L[first] = count - 1;
 48         }
 49         if(!dancing(1))
 50             cout << "NO" << endl;
 51     }
 52 
 53     return    0;
 54 }
 55 
 56 void    ini(int col)
 57 {
 58     U[HEAD] = D[HEAD] = H[HEAD] = C[HEAD] = HEAD;
 59     R[HEAD] = 1;
 60     L[HEAD] = col;
 61 
 62     int    front = HEAD;
 63     for(int i = 1;i <= col;i ++)
 64     {
 65         U[i] = D[i] = i;
 66         L[i] = front;
 67         R[i] = HEAD;
 68         R[front] = i;
 69         front = i;
 70 
 71         C[i] = i;
 72         H[i] = 0;
 73     }
 74 }
 75 
 76 bool    dancing(int k)
 77 {
 78     int    c = R[HEAD];
 79     if(c == HEAD)
 80     {
 81         output();
 82         return    true;
 83     }
 84 
 85     remove(C[c]);
 86     for(int i = D[c];i != c;i = D[i])
 87     {
 88         ANS[k] = H[i];
 89         for(int j = R[i];j != i;j = R[j])
 90             remove(C[j]);
 91         if(dancing(k + 1))
 92             return    true;
 93         for(int j = L[i];j != i;j = L[j])
 94             resume(C[j]);
 95     }
 96     resume(C[c]);
 97 
 98     return    false;
 99 }
100 
101 void    output(void)
102 {
103     int    i,j;
104     for(i = 1;ANS[i];i ++);
105     cout << i - 1 << " ";
106     for(j = 1;j < i - 1;j ++)
107         cout << ANS[j] << " ";
108     cout << ANS[j] << endl;
109 }
110 
111 void    remove(int c)
112 {
113     R[L[c]] = R[c];
114     L[R[c]] = L[c];
115 
116     for(int i = D[c];i != c;i = D[i])
117         for(int j = R[i];j != i;j = R[j])
118         {
119             D[U[j]] = D[j];
120             U[D[j]] = U[j];
121         }
122 }
123 
124 void    resume(int c)
125 {
126     R[L[c]] = c;
127     L[R[c]] = c;
128 
129     for(int i = U[c];i != c;i = U[i])
130         for(int j = R[i];j != i;j = R[j])
131         {
132             D[U[j]] = j;
133             U[D[j]] = j;
134         }
135 }