//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,avx512f")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <iostream>
#include <iomanip>
#include <string>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <stack>
#include <queue>
#include <bitset>
#include <numeric>
#include <cassert>
#include <memory>
#include <random>
#include <functional>
#include <complex>
#include <immintrin.h>
#ifdef DEBUG
#include "./Lib/debug_VC.hpp"
#include "./Lib/Timer.hpp"
#include "./Lib/sample.hpp"
#else
#define dump(...)
#endif

/* macro */
#define FOR(i, b, e) for(ll i = (ll)(b); i < (ll)(e); ++i)
#define RFOR(i, b, e) for(ll i = (ll)(e-1); i >= (ll)(b); --i)
#define REP(i, n) FOR(i, 0, n)
#define RREP(i, n) RFOR(i, 0, n)
#define REPC(x,c) for(const auto& x:(c))
#define REPI2(it,b,e) for(auto it = (b); it != (e); ++it)
#define REPI(it,c) REPI2(it, (c).begin(), (c).end())
#define RREPI(it,c) REPI2(it, (c).rbegin(), (c).rend())
#define REPI_ERACE2(it, b, e) for(auto it = (b); it != (e);)
#define REPI_ERACE(it, c) REPI_ERACE2(it, (c).begin(), (c).end())
#define ALL(x) (x).begin(),(x).end()
#define cauto const auto&
/* macro func */
template<class T>
inline auto sort(T& t) { std::sort(ALL(t)); }
template<class T>
inline auto rsort(T& t) { std::sort((t).rbegin(), (t).rend()); }
template<class T>
inline auto unique(T& t) { (t).erase(unique((t).begin(), (t).end()), (t).end()); }
template<class T, class S>
inline auto chmax(T& t, const S& s) { if (s > t) { t = s; return true; } return false; }
template<class T, class S>
inline auto chmin(T& t, const S& s) { if (s < t) { t = s; return true; } return false; }
inline auto BR() { std::cout << "\n"; }

/* type define */
using ll = long long;
using PAIR = std::pair<ll, ll>;
using VS = std::vector<std::string>;
using VL = std::vector<long long>;
using VVL = std::vector<VL>;
using VVVL = std::vector<VVL>;
using VD = std::vector<double>;
template<class T>
using V = std::vector<T>;

/* using std */
using std::cout;
constexpr char endl = '\n';
using std::cin;
using std::pair;
using std::string;
using std::stack;
using std::queue;
using std::vector;
using std::list;
using std::map;
using std::unordered_map;
using std::multimap;
using std::unordered_multimap;
using std::set;
using std::unordered_set;
using std::unordered_multiset;
using std::multiset;
using std::bitset;
using std::priority_queue;

/* Initial processing  */
struct Preprocessing { Preprocessing() { std::cin.tie(0); std::ios::sync_with_stdio(0); }; }_Preprocessing;

/* Remove the source of the bug */
signed pow(signed, signed) { assert(false); return -1; }

/* define hash */
namespace std {
template <>	class hash<std::pair<ll, ll>> { public:	size_t operator()(const std::pair<ll, ll>& x) const { return hash<ll>()(1000000000 * x.first + x.second); } };
}

/* input */
template<class T> std::istream& operator >> (std::istream& is, vector<T>& vec) { for (T& x : vec) is >> x; return is; }

/* constant value */
constexpr ll MOD = 1000000007;
//constexpr ll MOD = 998244353;

//=============================================================================================;

std::unordered_map<ll, ll> prime_decomposition(ll n) {
	/*
	ll i = 2;
	std::unordered_map<ll, ll> table{};
	while (i * i <= n) {
		while (n % i == 0) {
			n /= i;
			table[i]++;
		}++i;
	}
	if (n > 1) {
		table[n]++;
		return table;
	}
	return table;*/
	unordered_map<ll, ll> mp;
	while (n % 2 == 0) { mp[2]++; n /= 2; }
	while (n % 5 == 0) { mp[5]++; n /= 5; }
	return mp;
}

class CumulativeSum2D {
private:
	const ll h;
	const ll w;
	std::vector<std::vector<ll>> sumList;
public:

	CumulativeSum2D() = delete;
	CumulativeSum2D(const std::vector<std::vector<ll>>& v) :
		h(v.size()),
		w(v[0].size()),
		sumList(h + 1, std::vector<ll>(w + 1)) {
		for (ll i = 0; i < h; ++i) for (ll j = 0; j < w; ++j) {
			sumList[i + 1][j + 1] = v[i][j];
		}
		for (ll i = 0; i < h; ++i) for (ll j = 0; j < w + 1; ++j) {
			sumList[i + 1][j] += sumList[i][j];
		}
		for (ll i = 0; i < h + 1; ++i) for (ll j = 0; j < w; ++j) {
			sumList[i][j + 1] += sumList[i][j];
		}
	}
	ll get(ll y, ll x) {
		return sumList[y + 1][x + 1];
	}
	ll get(ll y1, ll x1, ll y2, ll x2) {
		if (y2 < y1 || x2 < x1) { return 0LL; }
		x1 = std::max(x1, 0LL); y1 = std::max(y1, 0LL);
		y2 = std::min(y2, h - 1); x2 = std::min(x2, w - 1);
		return sumList[y2 + 1][x2 + 1] + sumList[y1][x1] -
			sumList[y2 + 1][x1] - sumList[y1][x2 + 1];
	}
};


signed main() {
	ll n;
	cin >> n;
	VS v(n);
	cin >> v;

	constexpr ll mx2 = 45;
	constexpr ll mx5 = 20;
	constexpr ll mxd = 20;
	VVL w(mx2, VL(mx5));
	VVL d2(mxd, VL(mx2)), d5(mxd, VL(mx5));
	VL d0(mxd);

	REPC(x, v) {
		bool flg = false;
		ll d = 0;
		ll val = 0;
		REPC(c, x) {
			if (c == '.') {
				flg = true;
				continue;
			}
			if (flg) { ++d; }
			val *= 10;
			val += (c - '0');
		}
		auto dc = prime_decomposition(val);
		auto f2 = dc.find(2) != dc.end();
		auto f5 = dc.find(5) != dc.end();
		if (f2 && f5) {
			ll mn = std::min(std::min(dc[2], dc[5]), d);
			d -= mn;
			dc[2] -= mn;
			dc[5] -= mn;
			if (dc[2] == 0) { f2 = false; }
			if (dc[5] == 0) { f5 = false; }
		}

		if (d == 0) {
			ll mn = std::min(dc[2], dc[5]);
			++w[dc[2]][dc[5]];
		} else {
			if (f2) {
				++d2[d][dc[2]];
			} else if (f5) {
				++d5[d][dc[5]];
			} else {
				++d0[d];
			}
		}
	}
	auto sum = CumulativeSum2D(w);
	ll ans = 0;
	REP(i, mx2) REP(j, mx5) {
		ans += w[i][j] * (w[i][j] - 1) / 2;
		FOR(l, j + 1, mx5) {
			ans += w[i][j] * w[i][l];
		}
		ans += w[i][j] * sum.get(i + 1, 0, mx2 + 1, mx5 + 1);

		REP(k, mxd)REP(l, mx2) {
			// 2:i, 5:j d:k
			ll mn = std::min(i, j);
			ll d = k - mn;
			if (d <= 0) {
				ans += w[i][j] * d2[k][l];
				continue;
			}
			if (l < d) { continue; }
			if ((j - mn) >= d) {
				ans += w[i][j] * d2[k][l];
			}
		}
		REP(k, mxd)REP(l, mx5) {
			// 2:i, 5:j d:k
			ll mn = std::min(i, j);
			ll d = k - mn;
			if (d <= 0) {
				ans += w[i][j] * d5[k][l];
				continue;
			}
			if (l < d) { continue; }
			if ((i - mn) >= d) {
				ans += w[i][j] * d5[k][l];
			}
		}
		REP(k, mxd) {
			ll mn = std::min(i, j);
			ll d = k - mn;
			if (d <= 0) {
				ans += w[i][j] * d0[k];
			}
		}
	}
	REP(i, mxd)REP(j, mx2)REP(k, mxd)REP(l, mx5) {
		ll d = i + k;
		ll u = std::min(j, l);
		if (u >= d) {
			ans += d2[i][j] * d5[k][l];
		}
	}

	cout << ans << endl;
	//dump(w, d2, d5, d0);
}






Measured memory_bytes: 9480