#include <iostream>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>
#include <math.h>
#include <iomanip>
#include <limits>
#include <list>
#include <queue>
#include <tuple>
#include <map>
#include <stack>
#include <set>
#include <bitset>
#include <functional>
#include <cassert>
using namespace std;
#define fast_io ios_base::sync_with_stdio (false) ; cin.tie(0) ; cout.tie(0) ;
#define ll long long int
#define rep(i,n) for(int i=0; i<(int)(n); i++)
#define reps(i,n) for(int i=1; i<=(int)(n); i++)
#define REP(i,n) for(int i=n-1; i>=0; i--)
#define REPS(i,n) for(int i=n; i>0; i--)
#define MOD (long long int)(1e9+7)
#define INF (int)(1e9)
#define LINF (long long int)(1e18)
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
#define all(v) v.begin(), v.end()
typedef pair<int, int> Pii;
typedef pair<ll, ll> Pll;

ll mpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = mpow(a,b/2); return memo*memo%MOD;}
  else return mpow(a,b-1) * a % MOD;
}
ll lpow(ll a, ll b){
  if(b==0) return 1;
  else if(b%2==0){ll memo = lpow(a,b/2); return memo*memo;}
  else return lpow(a,b-1) * a;
}
ll gcd(ll a, ll b){
  if(b==0) return a;
  else return gcd(b, a%b);
}
vector<ll> kaijo_memo;
ll kaijo(ll n){
  if(kaijo_memo.size() > n) return kaijo_memo[n];
  if(kaijo_memo.size() == 0) kaijo_memo.push_back(1);
  while(kaijo_memo.size() <= n) kaijo_memo.push_back(kaijo_memo[kaijo_memo.size()-1] * kaijo_memo.size() % MOD);
  return kaijo_memo[n];
}
vector<ll> gyaku_kaijo_memo;
ll gyaku_kaijo(ll n){
  if(gyaku_kaijo_memo.size() > n) return gyaku_kaijo_memo[n];
  if(gyaku_kaijo_memo.size() == 0) gyaku_kaijo_memo.push_back(1);
  while(gyaku_kaijo_memo.size() <= n) gyaku_kaijo_memo.push_back(gyaku_kaijo_memo[gyaku_kaijo_memo.size()-1] * mpow(gyaku_kaijo_memo.size(), MOD-2) % MOD);
  return gyaku_kaijo_memo[n];
}

ll nCr(ll n, ll r){
  if(n == r) return 1;//0個の丸と-1個の棒みたいな時に時に効く？不安.
  if(n < r || r < 0) return 0;
  ll ret = 1;
  if(n <= 1e7){
    ret *= kaijo(n); ret %= MOD;
    ret *= gyaku_kaijo(r); ret %= MOD;
    ret *= gyaku_kaijo(n-r); ret %= MOD;
  }else{
    rep(i,r){
      ret *= n-i; ret %= MOD;
      ret *= mpow(r-i, MOD-2); ret %= MOD;
    }
  }
  return ret;
}

int main(void){
  fast_io
  cout<<fixed<<setprecision(15);

  ll n;
  cin>>n;
  vector<ll> A(n), B(n);
  rep(i,n){
    string s;cin>>s;
    int idx = 0;
    while(idx < s.size() && s[idx] != '.'){
      idx++;
    }
    if(s.size() == idx){
      A[i] = stoll(s);
      B[i] = 0;
      continue;
    }
    B[i] = s.size() - 1 - idx;
    s.erase(s.begin() + idx);
    A[i] = stoll(s);
  }

  vector<ll> Two(n,0), Five(n,0), Ten(n,0);
  rep(i,n){
    ll a = A[i];
    while(a%2 == 0){
      a /= 2;
      Two[i]++;
    }
    while(a%5 == 0){
      a/=5;
      Five[i]++;
    }
  }

  rep(i,n){
    Ten[i] = min(Two[i], Five[i]);
    Two[i] -= Ten[i];
    Five[i] -= Ten[i];
    B[i] -= Ten[i];
  }

  //B, Two, Five
  ll count[40][100] = {};
  //B - min(Two,Five) <= 0 ならok
  rep(i,n){
    assert(Two[i] == 0 || Five[i] == 0);
    if(Two[i] > 0){
      count[B[i] + 10][Two[i]]++;
    }else if(Five[i] > 0){
      count[B[i] + 10][Five[i] + 50]++;
    }else{
      count[B[i] + 10][0]++;
    }
  }
  ll ans = 0;
  for(int b1 = -5; b1 <= 10; b1++){
    rep(x1,80){
      int mode1;
      if(x1 < 50){
        mode1 = 0;
      }else{
        mode1 = 50;
      }

      for(int b2 = -5; b2 <= 10; b2++){
        rep(x2,80){
          int mode2;
          if(x2 < 50){
            mode2 = 0;
          }else{
            mode2 = 50;
          }

          int bsum = b1 + b2;
          if(b1 == b2 && x1 == x2){
            ll c = count[b1 + 10][x1];
            if(bsum <= 0 && c >= 2){
              ans += c * (c-1);
            }
            continue;
          }
          int tensum = 0;
          if(mode1 != mode2){
            tensum = min(x1 - mode1, x2 - mode2);
          }
          bsum -= tensum;
          if(bsum <= 0){
            ll val = count[b1 + 10][x1] * count[b2 + 10][x2];
            ans += val;
            //if(val > 0) cout<<b1<<" "<<(mode1==0?"2:":"5:")<<x1 - mode1<<" "<<b2<<" "<<(mode2==0?"2:":"5:")<<x2 - mode2<<" "<<val<<endl;
          }
        }
      }
    }
  }
  cout<<ans/2<<endl;
  return 0;
}

Measured memory_bytes: 11052