ソースコード
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)
#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()
#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))
// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD
int n;
int a[125252];
int main(){
scanf("%d",&n);
REP(i,n)scanf("%d",a+i);
sort(a,a+n);
ll ans = 0;
REP(i,n){
int cur = a[i];
int cnt = 1;
while(i+1<n && a[i+1]==cur)i++,cnt++;
if(ans==0){
ans = cnt;
continue;
}
ll tmp = ans * cnt % MOD;
ans += tmp;
ans %= MOD;
}
printf("%lld\n", ans);
return 0;
}