1 #include<bits/stdc++.h>
 2 using namespace std;
 3 const int N=25,M=10;
 4 int G,B,S,n,x,a[N],b[N],c[N][M],f[(1<<21)+5];
 5 int main()
 6 {
 7     while ((scanf("%d%d%d",&G,&B,&S))&&(G+B+S))
 8     {
 9         memset(c,0,sizeof(c));
10         for (int i=0;i<B;++i)
11         {
12             scanf("%d",&n);
13             for (int j=1;j<=n;++j)
14             {
15                 scanf("%d",&x);
16                 ++c[i][x];
17             }
18         }
19         f[0]=0;
20         for (int i=1;i<(1<<B);++i)
21         {
22             f[i]=-1e9;
23             memset(a,0,sizeof(a));
24             for (int j=0;j<B;++j)
25             if ((i&(1<<j))==0)
26             {
27                 for (int k=1;k<=G;++k)
28                 a[k]+=c[j][k],a[k]%=S;
29             }
30             for (int j=0;j<B;++j)
31             if (i&(1<<j))
32             {
33                 for (int k=1;k<=G;++k) b[k]=a[k];
34                 int cnt=0;
35                 for (int k=1;k<=G;++k)
36                 b[k]+=c[j][k],cnt+=b[k]/S,b[k]%=S;
37                 if (cnt) f[i]=max(f[i],cnt+f[i^(1<<j)]);
38                 else f[i]=max(f[i],-f[i^(1<<j)]);
39             }
40         }
41         printf("%d\n",f[(1<<B)-1]);
42     }
43     return 0;
44 }