//#pragma GCC optimize(3)
#include<bits/stdc++.h>
#define SZ(x) ((int)x.size())
#define uni(x) sort(all(x)),x.resize(unique(all(x))-x.begin());
#define GETPOS(c,x) (lower_bound(all(c),x)-c.begin())
#define lown1(x,val) low(in(x),val)-x
#define lowm1(x,val) low(im(x),val)-x
#define low1(x,nums,val) low(x+1,x+nums+1,val)-x
#define mst(x,val) memset((x),val,sizeof((x)))
#define ls rt<<1
#define rs rt<<1|1
#define lson rt<<1,l,M
#define rson rt<<1|1,M+1,r
#define PI acos(-1)
#define MM int M=(l+r)>>1;
#define fu(i,r,t) for(int i=r;i<=t;i++)
#define fd(i,r,t) for(int i=r;i>=t;i--)
#define fh(i,be,e) for(int i=head[be];~i;i=e[i].next)
#define fa(i,V) for(auto i:V)
#define far(i,V) for(auto &i:V)
#define IOS ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define lcm(a,b) ((a)*(b))/__gcd(a,b)
#define cp(i,ans) printf("%.if",ans);
#define cpp(i,ans) cout<<setprecision(i)<<fixed<<ans<<endl;
#define ppb pop_back
#define ppf pop_front
#define pb push_back
#define pf push_front
#define pq priority_queue
#define lowbit(x) ((x)&(-x))
#define all(V) V.begin(),V.end()
#define ms multiset
#define mod(x) ((x+mo_num)%mo_num)
#define vc vector
#define vct vector<int>
#define out(i) cout<<(i)<<endl;
#define fi first
#define se second
#define fun(i) fu(i,1,n)
#define fut(i) fu(i,1,t)
#define fum(i) fu(i,1,m)
#define ld long double
#define umap unordered_map
#define Umap unordered_map<int,int>
#define P pair<int,int>
#define SET set<int>
#define mk make_tuple
#define eps 1e-6
//Remember cancel"#define endl '\n'" in interactive questions or use "<<flush"
#define endl '\n'
#define low lower_bound
#define upp upper_bound
#define yn(key) out(key?"YES":"NO")
//#define yn(key) out(key?"Yes":"No")
#define in(i) i+1,i+1+n
#define im(i) i+1,i+1+m
#define ik(i,k) i+1,i+1+k
#define bffs(i) __builtin_ffs(i)
#define bcount(i) __builtin_popcount(i)
#define bone(i) ((1<<i)-1)
#define db double
#define ll long long
#define got(container,num) get<num-1>(container)
#define int long long
#define print(a,n) fun(i)cout<<a[i]<<(i!=n?' ':endl);
#define outcase(x) cout<<"Case #"<<(++case_of_T)<<": "<<x<<endl;
#define ptcase(x) printf("Case #%d: %d\n",++case_of_T,x);
#define plcase(x) printf("Case #%lld: %lld\n",++case_of_T,x);
using namespace std;
//Remember to cancel the line below and declare INT=INT_MAX/2; when you want to change long to int
const int INF=LLONG_MAX/4,SINF=0x3f3f3f3f,Lim=1<<20,MINF=LLONG_MAX;
//const int INF=INT_MAX/4;
// use C:printf("%.16f", x);  ->  printf("%.10f", x); can accelerate the program
//typedef unsigned long long ull; template<class T> void _R(T &x) { cin >> x; }void _R(int32_t &x) { scanf("%d", &x); }void _R(long long &x) { scanf("%lld", &x); }void _R(ull &x) { scanf("%llu", &x); }void _R(double &x) { scanf("%lf", &x); }void _R(char &x) { scanf(" %c", &x); }void _R(char *x) { scanf("%s", x); }void R() {}template<class T, class... U> void R(T &head, U &... tail) { _R(head); R(tail...); }template<class T> void _W(const T &x) { cout << x; }void _W(const int32_t &x) { printf("%d", x); }void _W(const long long &x) { printf("%lld", x); }void _W(const double &x) { printf("%.16f", x); }void _W(const char &x) { putchar(x); }void _W(const char *x) { printf("%s", x); }template<class T,class U> void _W(const pair<T,U> &x) {_W(x.F); putchar(' '); _W(x.S);}template<class T> void _W(const vector<T> &x) { for (auto i = x.begin(); i != x.end(); _W(*i++)) if (i != x.cbegin()) putchar(' '); }void W() {}template<class T, class... U> void W(const T &head, const U &... tail) { _W(head); putchar(sizeof...(tail) ? ' ' : '\n'); W(tail...); }
const int dx[]={0,0,-1,1},dy[]={-1,1,0,0};//up down left right
const int maxn=1e6+1e5;
int mo_num=1e9+7;
//const int mo_num=998244353;
int n,m,t,a[maxn],b[maxn],ans,case_of_T;
umap<int,Umap> sum;
P deal(int x)
{
    int n2=0,n5=0;
    while(x%2==0)x/=2,n2++;
    while(x%5==0)x/=5,n5++;
    return {n2,n5};
}
void solve()
{
    cin>>n;
    fun(i)
    {
        string k;
        cin>>k;
        string K=k;
        reverse(all(K));
        m=k.length();
        int fm=1,key=0;
        fum(j)
        {
            if(K[j-1]=='.') {
                key=1;
                break;
            }
            fm*=10;
        }
        if(!key)fm=1;
        int fz=0;
        fa(j,k)
        {
            if(j=='.')continue;
            fz=fz*10+j-'0';
        }
        int g=__gcd(fz,fm);
        fz/=g,fm/=g;
        P q=deal(fz);
        P w=deal(fm);
        int num2=q.fi-w.fi>9?9:q.fi-w.fi,num5=q.se-w.se>9?9:q.se-w.se;
        fu(j,-num2,9)
        {
            fu(l,-num5,9)
            {
                ans+=sum[j][l];
            }
        }
        sum[num2][num5]++;
    }
    out(ans)
    return ;
}
main()
{
    IOS
    int T=1;
    //cin>>T;
    while(T--)solve();
    return 0;
}


Measured memory_bytes: 3668