#include <bits/stdc++.h> 
using namespace std; 
typedef long long int ll;
typedef long double ld;
typedef unsigned long long int ull;
const long long int m=pow(10,9)+7;

int main() 
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    ll a,b,c,d,e,n;
    ll F[20][20] = {0};
    ll ans=0;
    cin>>n;
    for(int c1=0;c1<n;c1++)
    {
        ld x;
        cin >> x;
        a = round(x*1000000000.0);
        b = 0;
        c = 0;
        while(a%5 == 0){
            b++;
            a /= 5;
        }
        while(a%2 == 0){
            c++;
            a /= 2;
        }
        c = min(19ll, c);
        for(int c2=0;c2<20;c2++)
        {
            for(int c3=0;c3<20;c3++)
            {
                if(b+c2 >= 18 && c+c3 >= 18)
                    ans+=F[c2][c3];
            }
        }
        F[b][c]++;
    }
    cout<<ans<<"\n";
    return 0;
}