#define LOCAL
#define _USE_MATH_DEFINES
#include <array>
#include <cassert>
#include <cstdio>
#include <cstring>
#include <iostream>
#include <iomanip>
#include <string>
#include <sstream>
#include <vector>
#include <queue>
#include <stack>
#include <list>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <algorithm>
#include <complex>
#include <cmath>
#include <numeric>
#include <bitset>
#include <functional>
#include <random>
#include <ctime>

using namespace std;

template <typename A, typename B>
ostream& operator <<(ostream& out, const pair<A, B>& a) {
  out << "(" << a.first << "," << a.second << ")";
  return out;
}
template <typename T, size_t N>
ostream& operator <<(ostream& out, const array<T, N>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T>
ostream& operator <<(ostream& out, const vector<T>& a) {
  out << "["; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "]";
  return out;
}
template <typename T, class Cmp>
ostream& operator <<(ostream& out, const set<T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& v : a) { out << (first ? "" : ", "); out << v; first = 0;} out << "}";
  return out;
}
template <typename U, typename T, class Cmp>
ostream& operator <<(ostream& out, const map<U, T, Cmp>& a) {
  out << "{"; bool first = true;
  for (auto& p : a) { out << (first ? "" : ", "); out << p.first << ":" << p.second; first = 0;} out << "}";
  return out;
}
#ifdef LOCAL
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
#else
#define trace(...) 42
#endif
template <typename Arg1>
void __f(const char* name, Arg1&& arg1){
  cerr << name << ": " << arg1 << endl;
}
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args){
  const char* comma = strchr(names + 1, ',');
  cerr.write(names, comma - names) << ": " << arg1 << " |";
  __f(comma + 1, args...);
}

typedef long long int64;
typedef pair<int, int> ii;
#define SZ(x) (int)((x).size())
const int INF = 1 << 29;
const int MOD = 1e9 + 7;
mt19937 mrand(random_device{}());
int rnd(int x) { return mrand() % x; }

struct fast_ios {
  fast_ios() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
  };
} fast_ios_;

const int N = 50;
const int M = 20;

int main() {
  int n;
  scanf("%d", &n);
  vector<ii> a(n);
  for (int k = 0; k < n; ++k) {
    static char s[100];
    scanf("%s", s);
    int len = strlen(s), i;
    int64 p = 0;
    for (i = 0; i < len && s[i] != '.'; ++i) p = p * 10 + (s[i] - '0');
    int cnt = 0;
    for (++i; i < len; ++i) {
      ++cnt;
      p = p * 10 + (s[i] - '0');
    }
    cnt = 9 - cnt;
    while (cnt--) p = p * 10;
    // trace(k, p);
    while (p % 2 == 0) a[k].first++, p /= 2;
    while (p % 5 == 0) a[k].second++, p /= 5;
  }
  // trace(a);

  vector<vector<int>> cnt(N, vector<int>(M));
  int64 ret = 0;
  for (int i = 0; i < n; ++i) {
    int x = max(0, 18 - a[i].first);
    int y = max(0, 18 - a[i].second);
    ret += cnt[x][y];
    for (int u = a[i].first; u >= 0; --u) {
      for (int v = a[i].second; v >= 0; --v) {
        cnt[u][v]++;
      }
    }
  }
  printf("%lld\n", ret);
  return 0;
}


Measured memory_bytes: 4452