#define _CRT_SECURE_NO_WARNINGS
#define REL

#pragma GCC target ("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <deque>
#include <queue>
#include <iomanip>
#include <cstdio>
#include <unordered_map>
#include <unordered_set>
#include <map>
#include <string>
#include <set>
#include <bitset>
#include <cstdint>
#include <cstring>
#include <cassert>
#include <complex>
#include <stack> 
#include <random>

using namespace std;

typedef int64_t i64;
typedef long long LL;
typedef long long ll;
typedef long double LD;
typedef complex <LD> cld;
typedef unsigned int uint;
typedef complex <double> cd;
typedef unsigned long long ULL;

#define endl "\n"
#define dendl "\n\n"
#define mp make_pair
#define mt make_tuple
#define size(v) (int)v.size()
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()

/////////////////////////////////////////////////////////////////////

template <typename T>
T sqr(T a) {
	return a * a;
}

template <typename T>
int sign(T a) {
	if (a == 0)
		return 0;
	return (a > 0 ? 1 : -1);
}

template <typename T>
bool uax(T& a, const T b) {
	if (a < b) {
		a = b;
		return true;
	}
	return false;
}

template <typename T>
bool uin(T& a, const T b) {
	if (a > b) {
		a = b;
		return true;
	}
	return false;
}

template <typename T1, typename T2>
istream& operator >> (istream& in, pair<T1, T2>& p) {
	in >> p.first >> p.second;
	return in;
}

template <typename T1, typename T2>
ostream& operator << (ostream& out, pair<T1, T2>& p) {
	out << p.first << ' ' << p.second;
	return out;
}

mt19937_64 rnd(0);

const int LOG = 64;
const int N = (int)2e5 + 7;
const int MAXN = (int)1e6 + 7;
const int MOD = (int)1e9 + 7;
const int INF = (int)2e9 + 7;
const int CONST = 450;
const LL LINF = (i64)1e18;
const LD PI = 3.1415926535897932384626433832795;
const LD EPS = 1;

/////////////////////////////////////////////////////////////////////

int n, cnt[51][21];

void add(string& s) {
	int pos = -1;
	for (int i = 0; i < size(s); i++) {
		if (s[i] == '.')
			pos = i;
	}
	if (pos == -1) {
		s += '.';
		for (int i = 0; i < 9; i++)
			s += '0';
		return;
	}
	int cnt = size(s) - pos - 1;
	for (int i = cnt; i < 9; i++)
		s += '0';
}

LL parse(const string& s) {
	LL res = 0;
	for (char c : s) {
		if (c == '.')
			continue;
		res = 10 * res + c - '0';
	}
	return res;
}

void solve() {
	cin >> n;
	LL ans = 0;
	for (int i = 0; i < n; i++) {
		string s; cin >> s;
		add(s);
		LL x = parse(s);
		int cnt2 = 0, cnt5 = 0;
		while (x % 2 == 0)
			cnt2++, x /= 2;
		while (x % 5 == 0)
			cnt5++, x /= 5;
		for (int i = 50; i >= 0; i--) {
			if (cnt2 + i < 18)
				break;
			for (int j = 20; j >= 0; j--) {
				if (cnt5 + j < 18)
					break;
				ans += cnt[i][j];
			}
		}
		cnt[cnt2][cnt5]++;
	}
	cout << ans;
}

int main() {
	double start = clock();
#ifdef _DEBUG
	freopen("input.txt", "r", stdin);
	freopen("output.txt", "w", stdout);
	cout << fixed << setprecision(20);
	cerr << fixed << setprecision(20);
#else
	cout << fixed << setprecision(20);
	ios_base::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
	rnd.seed(time(0));
#endif

	int t = 1;
	for (int i = 0; i < t; i++) {
		solve();
	}

#ifdef _DEBUG
	cout << endl << "Time is " << (clock() - start) / 1000.0;
#endif
}

Measured memory_bytes: 3596