#include<cstdio>

 #include<iostream>

 #include<cmath>

 #include<cstring>

 #include<algorithm>

 #define ll long long

 const int Mod=,N=;

 ll jc[N+],jcny[N+],jcnys[N+],K[N+],p[N+],f[N+];

 int read(){

     int t=,f=;char ch=getchar();

     while (ch<''||ch>''){if (ch=='-')f=-;ch=getchar();}

     while (''<=ch&&ch<=''){t=t*+ch-'';ch=getchar();}

     return t*f;

 }

 int Pow(int a,int n){

     int res=;

     while (n){

         if (n%) res=((ll)res*a)%Mod;

         a=((ll)a*a)%Mod;

         n/=;

     }

     return res;

 }

 int main(){

     jc[]=;

     for (int i=;i<=;i++) jc[i]=(ll)(jc[i-]*i)%Mod;

     jcny[]=Pow(jc[],Mod-)%Mod;

     for (int i=;i>=;i--) jcny[i]=(ll)jcny[i+]*(i+)%Mod;

     for (int i=;i<=;i++) jcnys[i]=(ll)jcny[i]*jcny[i]%Mod;

     for (int i=;i<=;i++)

      if ((i&)&&jcny[i]) K[i]=Mod-jcny[i];else K[i]=jcny[i];

     int n=read();

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

         int x=read();p[x]++;

     }

     f[]=;

     for (int k=,tot=;k<=n;k++){

         if (p[k]==) continue;

         tot+=p[k];

         for (int i=tot;i>=;i--){

             f[i]=(ll)f[i]*jcnys[p[k]]%Mod;

             for (int j=;j<=p[k]&&j<=i;j++)

              f[i]=((ll)f[i-j]*K[j]%Mod*jcnys[p[k]-j]+f[i])%Mod;

         }

     }

     ll ans=;

     for (int i=;i<=n;i++)

      ans=((ll)jc[n-i]*f[i]+ans)%Mod;

     for (int i=;i<=n;i++)

      ans=(ll)ans*jc[p[i]]%Mod;

     printf("%I64d\n",ans);

 }