Big number

/// too big number multiplication handled with __int128_t + Hashing
/// Practice Problem : https://atcoder.jp/contests/abc339/tasks/abc339_f 

#include <bits/stdc++.h>
using namespace std;
#define int long long
__int128_t M = 10000000000000000007;

__int128_t hsh (string &s)

{
    __int128_t ans = 0;
    for (int i=0; i<s.size(); i++)
    {
        ans*=10;
        ans+=s[i]-'0';
        ans%=M;
        // cout <<"ans=" <<ans <<"\n";
    }
    return ans;
}







signed main()
{

    ios_base::sync_with_stdio(0);
    cin.tie(NULL);

    int n; cin >>n;
    vector <string> x(n);
    vector <__int128_t> v(n);
    map<__int128_t, int> mp;
    int i=0;
    for (auto &it: x) {cin >>it; v[i]=hsh(it); mp[v[i]]++;  i++; }
    int ans =0;
    for (int i=0; i<n; i++)
    {
        for (int j=0; j<n; j++)
        {
            __int128_t mul = v[i]*v[j];
            mul%=M;
            ans+=mp[mul];
            // cout <<"ans=" <<ans <<"\n";
        }
    }

    cout <<ans <<"\n";

}