#include <bits/stdc++.h>
using namespace std;
using lint = long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template <typename T> void ndarray(vector<T> &vec, int len) { vec.resize(len); }
template <typename T, typename... Args> void ndarray(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); }
template <typename V, typename T> void ndfill(V &x, const T &val) { x = val; }
template <typename V, typename T> void ndfill(vector<V> &vec, const T &val) { for (auto &v : vec) ndfill(v, val); }
template <typename T> bool chmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; }
template <typename T> bool chmin(T &m, const T q) { if (m > q) {m = q; return true;} else return false; }
template <typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template <typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
template <typename T> vector<T> srtunq(vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; }
template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <typename... T> istream &operator>>(istream &is, tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename... T> ostream &operator<<(ostream &os, const tuple<T...> &tpl) { std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os; }
template <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << '(' << pa.first << ',' << pa.second << ')'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
#ifdef HITONANODE_LOCAL
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl
#else
#define dbg(x)
#endif

lint is_int(string S)
{
    dbg(S);
    int k = 0;
    while (k < S.length() and S[k] != '.') k++;
    dbg(k);
    if (k == S.length()) return stoll(S);
    FOR(i, k + 1, S.length()) if (S[i] != '0') return false;
    return stoll(S);
}

int main()
{
    int N;
    cin >> N;

    // vector cnt(15, vector<int>(15, 0));
    constexpr int B = 40;
    vector req(B * 2 + 1, vector<lint>(B * 2 + 1, 0));

    lint nb_int = 0;
    REP(_, N)
    {
        string Astr;
        cin >> Astr;
        dbg(Astr);
        if (is_int(Astr))
        {
            dbg("INT");
            nb_int++;
            lint a = stoll(Astr);
            // integer
            int cnt2 = 0, cnt5 = 0;
            while (a % 2 == 0) cnt2++, a /= 2;
            while (a % 5 == 0) cnt5++, a /= 5;
            req[cnt2 + B][cnt5 + B]++;
            // REP(d1, cnt2 + 1) REP(d2, cnt5 + 1) cnt[d1][d2]++;
            dbg((pint(cnt2, cnt5)));
        }
        else
        {
            dbg("FLOAT");
            int k = 0;
            while (k < Astr.length() and Astr[k] != '.') k++;

            int cnt10 = Astr.length() - k - 1;
            lint a = stoll(Astr.substr(0, k) + Astr.substr(k + 1));
            // integer
            int cnt2 = 0, cnt5 = 0;
            while (a % 2 == 0) cnt2++, a /= 2;
            while (a % 5 == 0) cnt5++, a /= 5;
            cnt2 = cnt10 - cnt2, cnt5 = cnt10 - cnt5;
            cnt2 *= -1, cnt5 *= -1;
            dbg(pint(cnt2, cnt5));
            req[B + cnt2][B + cnt5]++;
        }
    }
    lint ret = 0;
    REP(i, req.size()) REP(j, req[i].size()) REP(k, req.size()) REP(l, req[k].size())
    {
        if (i + k - B * 2 >= 0 and j + l - B * 2 >= 0)
        {
            if (i == k and j == l) ret += req[i][j] * (req[k][l] - 1);
            else ret += req[i][j] * req[k][l];
        }
    }
    cout << ret / 2 << '\n';
}


Measured memory_bytes: 3712