#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n,a[500000],ans;
ll s[500000];
bool check()
{
	int flag=0;
	for(int q=1;q<=n;q++) s[a[q]]++;
	for(int q=1;q<=n;q++) if(s[q]!=1) flag=1;
	if(flag==0)
	{
		cout<<n*(n-1)/2;
		return 1;
	}
	return 0;
}
int main(){
	freopen("charger.in","r",stdin);
	freopen("charger.out","w",stdout);
cin>>n;
for(int q=1;q<=n;q++) cin>>a[q];
if(check()) return 0;
for(int q=1;q<=n;q++)
{
	memset(s,0,sizeof(s));
	for(int w=q+1;w<=n;w++)
	{
		if(!s[a[w]]&&!s[a[q]]&&a[q]!=a[w]) ans++;
		s[a[w]]++;
	}
}
cout<<ans;
return 0;
}