#include <string>
#include <vector>
#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<stack>
#include<queue>
#include<cmath>
#include<algorithm>
#include<functional>
#include<list>
#include<deque>
#include<bitset>
#include<set>
#include<map>
#include<unordered_map>
#include<unordered_set>
#include<cstring>
#include<sstream>
#include<complex>
#include<iomanip>
#include<numeric>
#include<cassert>
#include<random>
#define X first
#define Y second
#define pb push_back
#define rep(X,Y) for (int (X) = 0;(X) < (int)(Y);++(X))
#define reps(X,S,Y) for (int (X) = (int)(S);(X) < (int)(Y);++(X))
#define rrep(X,Y) for (int (X) = (int)(Y)-1;(X) >=0;--(X))
#define rreps(X,S,Y) for (int (X) = (int)(Y)-1;(X) >= (int)(S);--(X))
#define repe(X,Y) for ((X) = 0;(X) < (Y);++(X))
#define peat(X,Y) for (;(X) < (Y);++(X))
#define all(X) (X).begin(),(X).end()
#define rall(X) (X).rbegin(),(X).rend()
#define eb emplace_back
#define UNIQUE(X) (X).erase(unique(all(X)),(X).end())
#define Endl endl
#define NL <<"\n"
#define cauto const auto

using namespace std;
using ll=long long;
using pii=pair<int,int>;
using pll=pair<ll,ll>;
template<class T> using vv=vector<vector<T>>;
template<class T> inline bool MX(T &l,const T &r){return l<r?l=r,1:0;}
template<class T> inline bool MN(T &l,const T &r){return l>r?l=r,1:0;}
//#undef NUIP
#ifdef NUIP
#include "benri.h"
#else
#define out(args...)
#endif
#ifdef __cpp_init_captures
template<typename T>vector<T> table(int n, T v){ return vector<T>(n, v);}
template <class... Args> auto table(int n, Args... args){auto val = table(args...); return vector<decltype(val)>(n, move(val));}
#endif
template<class A,class B> pair<A,B> operator+(const pair<A,B> &p,const pair<A,B> &q){ return {p.X+q.X,p.Y+q.Y};}
template<class A,class B,class C,class D> pair<A,B>& operator+=(pair<A,B> &p,const pair<C,D> &q){ p.X+=q.X; p.Y+=q.Y; return p;}
template<class A,class B> pair<A,B> operator-(const pair<A,B> &p,const pair<A,B> &q){ return {p.X-q.X,p.Y-q.Y};}
template<class A,class B,class C,class D> pair<A,B>& operator-=(pair<A,B> &p,const pair<C,D> &q){ p.X-=q.X; p.Y-=q.Y; return p;}
template<class A,class B> istream& operator>>(istream &is, pair<A,B> &p){ is>>p.X>>p.Y; return is;}
template<class T=ll> T read(){ T re; cin>>re; return move(re);}
template<class T=ll> T read(const T &dec){ T re; cin>>re; return re-dec;}
template<class T=ll> vector<T> readV(const int sz){ vector<T> re(sz); for(auto &x:re) x=read<T>(); return move(re);}
template<class T=ll> vector<T> readV(const int sz, const T &dec){ vector<T> re(sz); for(auto &x:re) x=read<T>(dec); return move(re);}
vv<int> readG(const int &n,const int &m){ vv<int> g(n); rep(_,m){ cauto a=read<int>(1),b=read<int>(1); g[a].pb(b); g[b].pb(a);} return move(g);}
vv<int> readG(const int &n){ return readG(n,n-1);}
const ll MOD=1e9+7; //998244353

int main(){
  ios_base::sync_with_stdio(false); cin.tie(0);
  cout<<fixed<<setprecision(0);
	cauto n=read();
	cauto ss=readV<string>(n);
	vector<pii> ps;
	for(auto s:ss){
		int a=0,b=0;
		rep(i,s.size())if(s[i]=='.'){
			a-=s.size()-i-1;
			b-=s.size()-i-1;
			s=s.substr(0,i)+s.substr(i+1);
		}
		ll x=0;
		for(char c:s) (x*=10)+=c-'0';
		out(s,x,1);
		while(x%2==0) x/=2, ++a;
		while(x%5==0) x/=5, ++b;
		ps.eb(a,b);
	}
	out(n,ss,ps,1);

	auto cnt=table(55,55,0ll);
	cauto t=10;
	for(auto [a,b]:ps) ++cnt[a+t][b+t];
	ll re=0;
	rep(a,55)rep(b,55)rep(A,55)if(a+A>=t+t)rep(B,55)if(b+B>=t+t){
			if(cnt[a][b]&&cnt[A][B]) out(a,b,A,B,1);
			if(a==A && b==B){
				auto tmp=cnt[a][b];
				re+=tmp*(tmp-1);
			}else{
				re+=cnt[a][b]*cnt[A][B];
			}
		}
	cout<<re/2 NL;
  return 0;
}


Measured memory_bytes: 11476