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


#include "boost/multiprecision/cpp_int.hpp"
#include "boost/multiprecision/cpp_dec_float.hpp"
namespace mp = boost::multiprecision;
typedef mp::cpp_int LL;
typedef mp::number<mp::cpp_dec_float<1024>> DD;// 仮数部が1024ビットの浮動小数点数型(TLEしたら小さくする)

 
typedef long double dd;
#define i_7 (ll)(1E9+7)
//#define i_7 998244353
#define i_5 i_7-2
ll mod(ll a){
    ll c=a%i_7;
    if(c>=0)return c;
    return c+i_7;
}
typedef pair<ll,ll> l_l;
typedef pair<dd,dd> d_d;
ll inf=(ll)1E16;
#define rep(i,l,r) for(ll i=l;i<=r;i++)
#define rrep(i,r,l) for(ll i=r;i>=l;i--)
#define pb push_back
ll max(ll a,ll b){if(a<b)return b;else return a;}
ll min(ll a,ll b){if(a>b)return b;else return a;}
void Max(ll &pos,ll val){pos=max(pos,val);}//Max(dp[n],dp[n-1]);
void Min(ll &pos,ll val){pos=min(pos,val);}
void Add(ll &pos,ll val){pos=mod(pos+val);}
dd EPS=1E-12;
#define fastio ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define fi first
#define se second
#define endl "\n"  //インタラクティブで消す！！！！！！！！！！！！！！！！！！！！！
#define SORT(v) sort(v.begin(),v.end())
#define ERASE(v) v.erase(unique(v.begin(),v.end()),v.end())
#define POSL(v,x) (lower_bound(v.begin(),v.end(),x)-v.begin())
#define POSU(v,x) (upper_bound(v.begin(),v.end(),x)-v.begin())
template<class T,class S>
inline bool chmax(T &a, S b) {
    if(a < b) {
        a = b;
        return true;
    }
    return false;
}
template<class T,class S>
inline bool chmin(T &a, S b) {
    if(a > b) {
        a = b;
        return true;
    }
    return false;
}

void mod_print(ll k){
    ll P=50000;
    rep(y,1,P){
        ll x=mod(y*k);
        
        if(abs(x)<=P||x+P>=i_7){
            if(x+P>=i_7){
                x-=i_7;
            }
            cout<<x<<"/"<<y<<endl;
            //cout<<setprecision(5)<<(dd)x/(dd)y;
            return;
        }
    }
    cout<<"nun"<<endl;
}
#define all(c) c.begin(),c.end()
typedef vector<ll> vl;
//////////////////////////


l_l cal(ll n){
    if(n==0){
        return (l_l){100,100};
    }
    l_l ret;
    while(n>0){
        if(n%2==0){
            n/=2;
            ret.fi++;
        }else{
            break;
        }
    }
    while(n>0){
        if(n%5==0){
            n/=5;
            ret.se++;
        }else{
            break;
        }
    }
    return ret;
}

ll conv(string s){
    ll n=s.size();
    ll ret=0;
    ll bai=1;
    rrep(i,n-1,0){
        if(s[i]=='.')continue;
        ret+=bai*(s[i]-'0');
        bai*=10;
    }
    ll cnt=0;
    rrep(i,n-1,0){
        if(s[i]=='.'){
            return ret*powl(10,9-cnt);
            break;
        }
        cnt++;
    }
    return ret*powl(10,9);
}

int main(){fastio
    ll n;cin>>n;
    ll x[n];
    rep(i,0,n-1){
        string s;cin>>s;
        x[i]=conv(s);
    }
  //  rep(i,0,n-1)cout<<x[i]<<endl;cout<<endl;
    l_l d[n];
    ll M=18;
    rep(i,0,n-1){
        d[i]=cal(x[i]);
        chmin(d[i].fi,18);
        chmin(d[i].se,18);
    }
    
  //  rep(i,0,n-1)cout<<d[i].fi<<" "<<d[i].se<<endl;cout<<endl;
    ll ans=0;
    ll cnt[M+1][M+1];memset(cnt,0,sizeof(cnt));
    rep(i,0,n-1){
        rep(x,M-d[i].fi,M){
            rep(y,M-d[i].se,M){
                ans+=cnt[x][y];
            }
        }
        cnt[d[i].fi][d[i].se]++;
    }
    
    cout<<ans<<endl;
    
    return 0;
}


Measured memory_bytes: 8288