#include <iostream>
#include<queue>
#include <algorithm>
#include <map>
#include<unordered_map>
#include <set>
#include <fstream>
#include <vector>
#include <math.h>
#include <iomanip>
#include <string>
#include <cstring>
using namespace std;
 
#define ll long long
 
ll mod = 1e9+7;
const int MaxN = 1e5+5;
int MOD = 998244353;
int bit[200000];
ll dem=0;
 
int main() {
	//freopen("CSBN.INP", "r", stdin);
	//freopen("CSBN.OUT", "w", stdout);
	ll n,x;
	cin >> n;
	unordered_map<int,int> mp;
    for(int i=1;i<=n;i++){
    	cin >> x;
    	mp[x]++;
	}
	for(auto &p : mp){
		dem += (p.second*(p.second-1))/2;
	}
	cout << dem;
	return 0;
}

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

NQo0IDUgNCA2IDEK

5
4 5 4 6 1