#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define uni(x) x.erase(unique(rng(x)),x.end())
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cerr<<#x<<" = "<<x<<endl;
#define PQ(T) priority_queue<T,v(T),greater<T> >
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
typedef long long int ll;
typedef unsigned uint;
typedef unsigned long long ull;
typedef pair<int,int> P;
typedef tuple<int,int,int> T;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<P> vp;
typedef vector<T> vt;
int getInt(){int x;scanf("%d",&x);return x;}
template<typename T>istream& operator>>(istream&i,v(T)&v){rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const v(T)&v){stringstream s;rep(i,sz(v))s<<' '<<v[i];return s.str().substr(1);}
template<typename T>ostream& operator<<(ostream&o,const v(T)&v){if(sz(v))o<<join(v);return o;}
template<typename T1,typename T2>istream& operator>>(istream&i,pair<T1,T2>&v){return i>>v.fi>>v.se;}
template<typename T1,typename T2>ostream& operator<<(ostream&o,const pair<T1,T2>&v){return o<<v.fi<<","<<v.se;}
template<typename T>bool mins(T& x,const T&y){if(x>y){x=y;return true;}else return false;}
template<typename T>bool maxs(T& x,const T&y){if(x<y){x=y;return true;}else return false;}
template<typename T>ll suma(const v(T)&a){ll res(0);for(auto&&x:a)res+=x;return res;}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
const int MX = 200005;

bool ok(P a, P b) {
  a.fi += b.fi;
  a.se += b.se;
  if (a.fi < 0) return false;
  if (a.se < 0) return false;
  return true;
}

int main() {
  int n;
  scanf("%d",&n);
  map<P,int> mp;
  rep(i,n) {
    string s;
    cin>>s;
    ll x = 1, a = 0;
    drep(i,sz(s)) {
      if (s[i] == '.') break;
      x *= 10;
      if (i == 0) x = 1;
    }
    rep(i,sz(s)) {
      if (s[i] == '.') continue;
      a = a*10+(s[i]-'0');
    }
    int e2 = 0, e5 = 0;
    while (x > 1) {
      if (a%10 == 0) {
        //
      } else if (a%5 == 0) {
        a *= 2;
        e2--;
      } else if (a%2 == 0) {
        a *= 5;
        e5--;
      } else {
        a *= 10;
        e2--; e5--;
      }
      a /= 10;
      x /= 10;
    }
    ll f = 1;
    while (a%2 == 0) {
      a /= 2;
      e2++;
    }
    while (a%5 == 0) {
      a /= 5;
      e5++;
    }
    mp[P(e2,e5)]++;
  }
  ll ans = 0;
  while (sz(mp)) {
    auto nt = mp.begin();
    P p = nt->fi;
    ll x = nt->se;
    mp.erase(nt);
    if (ok(p,p)) ans += x*(x-1)/2;
    for (auto q : mp) {
      if (ok(p,q.fi)) ans += x*q.se;
    }
  }
  cout<<ans<<endl;
  return 0;
}






















Measured memory_bytes: 3696