1 #include<iostream> 2 #include<cstdio> 3 #include<algorithm> 4 #include<vector> 5 #include<cstdlib> 6 #include<cmath> 7 #include<cstring> 8 using namespace std; 9 #define maxn 100001010 #define md (llg)(1000100000001007)11 #define MD 100000000712 #define md2 (llg)(5456145545456)13 #define md3 (llg)(100007)14 #define llg long long 15 #define yyj(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout);16 llg n,m,a[maxn],p[maxn],l,r;17 18 struct node19 {20     llg a1,a2,a3;21 }c[maxn];22 23 bool cmp(const node&a,const node&b)24 {25     if (a.a1==b.a1 && a.a2==b.a2) return a.a3<b.a3; 26     if (a.a1==b.a1) return a.a2<b.a2;27     return a.a1<b.a1;28 }29 30 int main()31 {32     srand(1346);33 //    yyj("C");34     p[0]=p[1]=1;35     for (llg i=2;i<=1000000;i++) p[i]=p[i-1]*i,p[i]%=MD;36     cin>>n>>m;37     llg inc=1;38     for (llg k=1;k<=n;k++)39     {40         llg x;41         inc=rand()%md+1; llg inc2=rand()%md+1,inc3=rand()%md+1;42         scanf("%I64d",&x);43         for (llg i=1;i<=x;i++) 44         {45             scanf("%I64d",&a[i]);46             c[a[i]].a1+=inc; c[a[i]].a2+=inc2; c[a[i]].a3+=inc3;47             c[a[i]].a1%=md; c[a[i]].a2%=md2; c[a[i]].a3%=md3;48         }49         inc*=2;50         inc%=md;51     }52     llg ans=1;53     sort(c+1,c+m+1,cmp);54     l=1;55     while (l<=m)56     {57         r=l;58         while (c[r+1].a1==c[l].a1 && c[r+1].a2==c[l].a2 && c[r+1].a3==c[l].a3 && r+1<=m) r++;59         ans*=p[r-l+1];60         ans%=MD;61         l=r+1;62     }63 //    for (llg i=1;i<=c[0];i++) ans*=n,ans%=MD; 64     cout<<ans;65     return 0;66 }