#include <bits/stdc++.h>
using namespace std;

#define llong long long 
#define len(x) ((int)x.size())
#define rep(i,n) for (int i = -1; ++ i < n; )
#define rep1(i,n) for (int i = 0; i ++ < n; )
#define rand __rand
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());  // or mt19937_64
template<class T = int> T rand(T range = numeric_limits<T>::max()) { return (T)(rng() % range); }

#define CONCAT_(x, y) x##y/*{{{*/
#define CONCAT(x, y) CONCAT_(x, y)
#ifdef LOCAL_DEBUG   
int __db_level = 0;
bool __db_same_line = false;
#define clog cerr << string(!__db_same_line ? __db_level * 2 : 0, ' ')
struct debug_block {
    function<void()> fn;
    void print_name() { __db_same_line = true; fn(); clog << endl; __db_same_line = false;  }
    debug_block(function<void()> fn_): fn(fn_) { clog << "{ "; print_name(); ++__db_level; }
    ~debug_block() { --__db_level; clog << "} "; print_name(); }
};
#define DB(args...) debug_block CONCAT(dbbl, __LINE__)([=]{ clog << args; })
#define deb(...)  if (1) { (clog << "[" #__VA_ARGS__ "] = [" << __VA_ARGS__) << "]"; if (!__db_same_line) clog << endl; }
#else
#define clog if (0) cerr
#define DB(...)
#define deb(...)
#endif
template<class T>
ostream& operator,(ostream& out, const T& thing) { return out << ", " << thing; }
template<class U, class V>
ostream& operator<<(ostream& out, const pair<U, V>& p) { return (out << "(" << p.first, p.second) << ")"; }
template<class A, class B>
ostream& operator<<(ostream& out, const tuple<A, B>& t) { return (out << "(" << get<0>(t), get<1>(t)) << ")"; }
template<class A, class B, class C>
ostream& operator<<(ostream& out, const tuple<A, B, C>& t) { return (out << "(" << get<0>(t), get<1>(t), get<2>(t)) << ")"; }
template<class T> ostream& operator<<(ostream& out, const vector<T>& container) { 
    out << "{";
    if (len(container)) out << container[0];
    rep1(i, len(container) - 1) out, container[i];
    return out << "}";
}
template<class x> vector<typename x::value_type> $v(const x& a) { return vector<typename x::value_type>(a.begin(), a.end()); }
#define ptrtype(x) typename iterator_traits<x>::value_type
template<class u> vector<ptrtype(u)> $v(u a, u b) { return vector<ptrtype(u)>(a, b); }/*}}}*/
// ACTUAL SOLUTION BELOW ////////////////////////////////////////////////////////////

pair<int, int> parse(string s) {
    DB(""; deb(s));
    bool has_period = false;
    for (char& c: s) if (c == '.') {
        c = ' ';
        has_period = true;
        break;
    }
    stringstream ss(s);
    llong u; ss >> u >> s;
    pair<int, int> ans(-len(s), -len(s));
    if (has_period) {
        rep(i, len(s)) u *= 10;
        deb(u, s);
        
        for (char& c: s) {
            if (c == '0') c = ' ';
            else break;
        }
        deb(s);
        
        deb(ss.str());
        ss = stringstream(s + " 0");
        deb(ss.str());
        llong v; ss >> v;
        u += v;
        deb(s, u, v);
    } else ans = {0, 0};
    
    while (u % 2 == 0) {
        ans.first += 1;
        u /= 2;
    }
    
    while (u % 5 == 0) {
        ans.second++;
        u /= 5;
    }
    deb(ans);
    return ans;
}

int main(void) {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    map<pair<int, int>, llong> cnt;
    int n; cin >> n >> ws;
    rep(i, n) {
        string s; getline(cin, s);
        cnt[parse(s)]++;
    }
    
    llong ans = 0;
    for (auto& [u, cu]: cnt) {
        for (auto & [v, cv]: cnt) {
            if (v < u) continue;
            if (u.first + v.first < 0) continue;
            if (u.second + v.second < 0) continue;
            if (u == v) ans += cu * (cu - 1) / 2;
            else ans += cu * cv;
            deb(u, v, cu, cv);
        }
    }
    cout << ans;

    return 0;
}

// Remember:
// - Multitest? REFRESHING the data!!!
// - Constrains for each set of data may differs. Should NOT USE the same max constant (maxn)
//   for all of them.
// vim: foldmethod=marker



Measured memory_bytes: 3648