#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define vll vector<long long>
#define MAXK 1000000
#define mapll map<long long,long long>
ll n;
map<ll,ll> ma;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    freopen("bailam.inp","r",stdin);
    freopen("bailam.out","w",stdout);
    cin>>n;
    if(n>=0){
        ll mo=12345678*2;
        ll ans=(n%mo)*((n-1)%mo);
        ans=ans%mo;
        cout<<ans/2;
        return 0;
    }
    ll ans=0;
    for(ll i=1;i<=n;i++){
        ll x;
        cin>>x;
        ans+=ma[x];
        ma[x]++;
    }
    cout<<ans;
    return 0;
}