#include <bits/stdc++.h>
#include <cassert>
typedef long long int ll;
using namespace std;

// @@ !! LIM(debug)
// --> f:<< debug
// ---- inserted function << from util.cc
template <typename T1, typename T2>
ostream& operator<< (ostream& os, const pair<T1,T2>& p) {
  os << "(" << p.first << ", " << p.second << ")";
  return os;
}

template <typename T1, typename T2, typename T3>
ostream& operator<< (ostream& os, const tuple<T1,T2,T3>& t) {
  os << "(" << get<0>(t) << ", " << get<1>(t)
     << ", " << get<2>(t) << ")";
  return os;
}

template <typename T1, typename T2, typename T3, typename T4>
ostream& operator<< (ostream& os, const tuple<T1,T2,T3,T4>& t) {
  os << "(" << get<0>(t) << ", " << get<1>(t)
     << ", " << get<2>(t) << ", " << get<3>(t) << ")";
  return os;
}

template <typename T>
ostream& operator<< (ostream& os, const vector<T>& v) {
  os << '[';
  for (auto it = v.begin(); it != v.end(); it++) {
    if (it != v.begin()) os << ", ";
    os << *it;
  }
  os << ']';

  return os;
}

template <typename T>
ostream& operator<< (ostream& os, const set<T>& v) {
  os << '{';
  for (auto it = v.begin(); it != v.end(); it++) {
    if (it != v.begin()) os << ", ";
    os << *it;
  }
  os << '}';

  return os;
}

template <typename T>
ostream& operator<< (ostream& os, const multiset<T>& v) {
  os << '{';
  for (auto it = v.begin(); it != v.end(); it++) {
    if (it != v.begin()) os << ", ";
    os << *it;
  }
  os << '}';

  return os;
}

template <typename T1, typename T2>
ostream& operator<< (ostream& os, const map<T1, T2>& mp) {
  os << '[';
  for (auto it = mp.begin(); it != mp.end(); it++) {
    if (it != mp.begin()) os << ", ";
    os << it->first << ": " << it->second;
  }
  os << ']';

  return os;
}

template <typename T, typename T2>
ostream& operator<< (ostream& os, const queue<T, T2>& orig) {
  queue<T, T2> que(orig);
  bool first = true;
  os << '[';
  while (!que.empty()) {
    T x = que.front(); que.pop();
    if (!first) os << ", ";
    os << x;
    first = false;
  }
  return os << ']';
}

template <typename T, typename T2, typename T3>
ostream& operator<< (ostream& os, const priority_queue<T, T2, T3>& orig) {
  priority_queue<T, T2, T3> pq(orig);
  bool first = true;
  os << '[';
  while (!pq.empty()) {
    T x = pq.top(); pq.pop();
    if (!first) os << ", ";
    os << x;
    first = false;
  }
  return os << ']';
}

template <typename T>
ostream& operator<< (ostream& os, const stack<T>& st) {
  stack<T> tmp(st);
  os << '[';
  bool first = true;
  while (!tmp.empty()) {
    T& t = tmp.top();
    if (first) first = false;
    else os << ", ";
    os << t;
    tmp.pop();
  }
  os << ']';
  return os;
}

#if __cplusplus >= 201703L
template <typename T>
ostream& operator<< (ostream& os, const optional<T>& t) {
  if (t.has_value()) os << "v(" << t.value() << ")";
  else               os << "nullopt";
  return os;
}
#endif

// ---- end <<
// ---- inserted library file debug.cc
template <class... Args>
string dbgFormat(const char* fmt, Args... args) {
  size_t len = snprintf(nullptr, 0, fmt, args...);
  char buf[len + 1];
  snprintf(buf, len + 1, fmt, args...);
  return string(buf);
}

template <class Head>
void dbgLog(Head&& head) {
  cerr << head << endl;
}

template <class Head, class... Tail>
void dbgLog(Head&& head, Tail&&... tail)
{
  cerr << head << " ";
  dbgLog(forward<Tail>(tail)...);
}

#if DEBUG
  #define DLOG(...)        dbgLog(__VA_ARGS__)
  #define DFMT(...)        cerr << dbgFormat(__VA_ARGS__) << endl
  #define DCALL(func, ...) func(__VA_ARGS__)
#else
  #define DLOG(...)
  #define DFMT(...)
  #define DCALL(func, ...)
#endif

#if DEBUG_LIB
  #define DLOG_LIB(...)        dbgLog(__VA_ARGS__)
  #define DFMT_LIB(...)        cerr << dbgFormat(__VA_ARGS__) << endl
  #define DCALL_LIB(func, ...) func(__VA_ARGS__)
#else
  #define DLOG_LIB(...)
  #define DFMT_LIB(...)
  #define DCALL_LIB(func, ...)
#endif

// ---- end debug.cc
// @@ !! LIM  -- end mark --

int main(/* int argc, char *argv[] */) {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout << setprecision(20);

  ll N; cin >> N;
  vector<vector<ll>> vec(19, vector(19, 0LL));
  for (ll _i = 0; _i < N; _i++) {
    string s; cin >> s;
    ll len = s.size();
    ll pt = -1;
    for (ll i = 0; i < len; i++) {
      if (s[i] == '.') {
	pt = i;
	break;
      }
    }
    ll two = 0;
    ll five = 0;
    if (pt == -1 || pt == len - 1) {
      ll x;
      if (pt == -1) x = stoi(s);
      else          x = stoi(s.substr(len-1));
      while (x % 2 == 0) {
	x /= 2;
	two++;
      }
      while (x % 5 == 0) {
	x /= 5;
	five++;
      }
    }else {
      string s1;
      if (pt == 0) s1 = "0";
      else         s1 = s.substr(0, pt);
      string s2 = s.substr(pt + 1);
      ll x1 = stoi(s1);
      ll x2 = stoi(s2);
      ll t = 1;
      ll y = s2.size();
      for (ll j = 0; j < y; j++) t *= 10;
      ll x = x1 * t + x2;
      while (x % 2 == 0) {
	x /= 2;
	two++;
      }
      while (x % 5 == 0) {
	x /= 5;
	five++;
      }
      two -= y;
      five -= y;
    }
    DLOG("s=", s, "two=", two, "five=", five);
    if (two >= 9) two = 9;
    if (five >= 9) five = 9;
    vec[two+9][five+9]++;
  }
    
  ll ans = 0;
  for (ll i = 0; i < 19; i++) {
    for (ll j = 0; j < 19; j++) {
      for (ll k = 18 - i; k < 19; k++) {
	if (k < i) continue;
	for (ll l = 18 - j; l < 19; l++) {
	  if (k == i && l < j) continue;
	  if (k == i && l == j) {
	    ans += vec[i][j] * (vec[i][j] - 1) / 2;
	  }else {
	    ans += vec[i][j] * vec[k][l];
	  }
	}
      }
    }
  }
  cout << ans << endl;

  return 0;
}



Measured memory_bytes: 3660