1 #include<bits/stdc++.h>

 2 using namespace std;

 3 long long n,k,s[6],f[16][16][16][16][16][6];

 4 long long dfs(int a,int b,int c,int d,int e,int p){

 5     if (f[a][b][c][d][e][p])return f[a][b][c][d][e][p];

 6     if (a)f[a][b][c][d][e][p]+=(a-(p==2))*dfs(a-1,b,c,d,e,1);

 7     if (b)f[a][b][c][d][e][p]+=(b-(p==3))*dfs(a+1,b-1,c,d,e,2);

 8     if (c)f[a][b][c][d][e][p]+=(c-(p==4))*dfs(a,b+1,c-1,d,e,3);

 9     if (d)f[a][b][c][d][e][p]+=(d-(p==5))*dfs(a,b,c+1,d-1,e,4);

10     if (e)f[a][b][c][d][e][p]+=e*dfs(a,b,c,d+1,e-1,5);

11     return f[a][b][c][d][e][p]=f[a][b][c][d][e][p]%1000000007+1000000007;

12 }

13 int main(){

14     scanf("%lld",&n);

15     for(int i=1;i<=n;i++){

16         scanf("%lld",&k);

17         s[k]++;

18     }

19     for(int i=1;i<=5;i++)f[0][0][0][0][0][i]=1;

20     printf("%lld",dfs(s[1],s[2],s[3],s[4],s[5],0)-1000000007);

21 }