//Arayi
//#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <math.h>
#include <vector>
#include <cstring>
#include <ctime>
#include <set>
#include <bitset>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <ctime>
#include <climits>
#include <cassert>
#include <chrono>
#include <random>
#include <complex>

#define fr first
#define sc second
#define MP make_pair
#define ad push_back
#define PB push_back
#define fastio ios_base::sync_with_stdio(false); cin.tie(0);
#define lli long long int
#define y1 arayikhalatyan
#define j1 jigglypuff
#define ld long double
#define itn int
#define pir pair<int, int> 
#define all(x) (x).begin(), (x).end()
#define str string
#define enl endl
#define en endl
#define cd complex<long double>
#define vcd vector<cd>
#define vii vector<int>
#define vlli vector<lli>
using namespace std;

lli gcd(lli a, lli b) { return (b == 0LL ? a : gcd(b, a % b)); }
ld dist(ld x, ld y1, ld x2, ld y2)
{
    return sqrt((x - x2) * (x - x2) + (y1 - y2) * (y1 - y2));
}
lli S(lli a)
{
    return (a * (a + 1LL)) / 2;
}
mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());
char vow[] = { 'a', 'e', 'i', 'o', 'u' };
int dx[] = { 1, -1, 0, 0, -1, -1, 1, 1, 0 };
int dy[] = { 0, 0, 1, -1, -1, 1, -1, 1, 0 };


const int N = 2e5 + 30;
const lli mod = 998244353;
const ld pi = acos(-1);
const int T = 238;
const ld e = 1e-13;

lli bp(lli a, lli b = mod - 2LL)
{
    lli ret = 1;
    while (b)
    {
        if (b & 1) ret *= a, ret %= mod;
        a *= a;
        a %= mod;
        b >>= 1;
    }
    return ret;
}
ostream& operator<<(ostream& c, pir a)
{
    c << a.fr << " " << a.sc;
    return c;
}
struct pt
{
    lli x, y;
    int ind;
    int bl;
    bool operator==(const pt& a)
    {
        return ind == a.ind;
    }
    bool operator<(const pt& b)
    {
        if (x == b.x) return y < b.y;
        return x < b.x;
    }
};





int n;
pir a[N];
lli fp[21][21];
lli pat;
int main()
{
    fastio;
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        lli sm = 0;
        str s;
        cin >> s;
        bool bl = false;
        for (int i = 0; i < s.length(); i++)
        {
            if (s[i] == '.')
            {
                s.erase(0, i + 1);
                bl = true;
                break;
            }
            sm *= 10LL;
            sm += s[i] - '0';
        }
        if (!bl) s = "";
        while (s.length() < 9) s += '0';
        for (int i = 0; i < 9; i++)
        {
            sm *= 10LL;
            sm += s[i] - '0';
        }
        //cout << sm << " ";
        int ss = 0, ss1 = 0;
        while (sm % 2LL == 0) sm /= 2LL, ss++;
        while (sm % 5LL == 0) sm /= 5LL, ss1++;
        a[i] = MP(min(18, ss), min(18, ss1));
        //cout << a[i].fr << " " << a[i].sc << endl;
    }
    for (int i = 0; i < n; i++)
    {
        lli ans = 0;
        for (int j = 18; j >= 18 - a[i].fr; j--)
        {
            for (int k = 18; k >= 18 - a[i].sc; k--)
            {
                ans += fp[j][k];
            }
        }
        pat += ans;
        fp[a[i].fr][a[i].sc]++;
    }
    cout << pat << endl;
    return 0;
}

/*

  __
*(><)*
  \/ /
  ||/
--||
  ||
  /\
 /  \
/    \
*/

Measured memory_bytes: 5184