#include<bits/stdc++.h>
using namespace std;
#pragma region Macros
#define ios\
    ios::sync_with_stdio(false);\
    cin.tie(nullptr);
#define VEC(type, name, size)\
    V<type> name(size);\
    IN(name)
#define VVEC(type, name, h, w)\
    VV<type> name(h, V<type>(w));\
    IN(name)
#define INT(...)\
    int __VA_ARGS__;\
    IN(__VA_ARGS__)
#define LL(...)\
    ll __VA_ARGS__;\
    IN(__VA_ARGS__)
#define STR(...)\
    string __VA_ARGS__;\
    IN(__VA_ARGS__)
#define CHAR(...)\
    char __VA_ARGS__;\
    IN(__VA_ARGS__)
#define DOUBLE(...)\
    DOUBLE __VA_ARGS__;\
    IN(__VA_ARGS__)
#define LD(...)\
    LD __VA_ARGS__;\
    IN(__VA_ARGS__)
template <class T> void scan(T &a) { cin >> a; }
template <class T> void scan(vector<T> &a) { for(auto &i : a) scan(i); }
template <class T, class L> void scan(pair<T, L> &p){ scan(p.first); scan(p.second); }
void IN() {}
template <class Head, class... Tail> void IN(Head &head, Tail &... tail) { scan(head); IN(tail...); }
template <class T> inline void print(T x){ cout << x << '\n';}
#define ll long long
#define ld long double
#define FOR(i,l,r) for(ll i=(l);i<(r);++i)
#define REP(i,n) FOR(i,0,n)
#define REPS(i,n) FOR(i,1,n+1)
#define RFOR(i,l,r) for(ll i=(l);i>=(r);--i)
#define RREP(i,n) RFOR(i,n-1,0)
#define RREPS(i,n) RFOR(i,n,1)
#define pb push_back
#define eb emplace_back
#define SZ(x) ((ll)(x).size())
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
template<class T = ll> using V = vector<T>;
template<class T = ll> using VV = V<V<T>>;
template<class T> inline bool chmin(T& a, T b) {if (a > b) {a = b; return true; }return false; }
template<class T> inline bool chmax(T& a, T b) {if (a < b) {a = b; return true; }return false; }
inline void Yes(bool b = true) {cout << (b ? "Yes" : "No") << '\n';}
inline void YES(bool b = true) {cout << (b ? "YES" : "NO") << '\n';}
inline void err(bool b = true) {if(b) {cout << -1 << '\n'; exit(0);}}
template<class T> inline void fin(bool b = true, T e = 0) {if(b) {cout << e << '\n'; exit(0);}}
template<class T> T Roundup_div(T x, T y) {return (x+(y-1))/y;}
template <typename T> T pow(T a, long long n, T e = 1) {T ret = e; while (n) {if (n & 1) ret *= a; a *= a; n >>= 1; } return ret; }
const ll INF = 1e18;
#pragma endregion

int main(){
    ios;
    INT(n);
    V<pair<int,int>> a(n);
    VV<> cum(201, V<>(201, 0));
    REP(i, n){
        string s; cin >> s;
        ll k = 0;
        ll tc = 0, fc = 0;
        bool flg = false;
        REP(j, SZ(s)){
            if(s[j] != '.'){
                k *= 10;
                k += (s[j] - '0');
                if(flg){
                    tc--; 
                    fc--;
                }
            }
            else flg = true;
        }
        while(k % 2 == 0){
            k /= 2;
            tc++;
        }
        while(k % 5 == 0){
            k /= 5;
            fc++;
        }
        cum[tc + 100][fc + 100]++;
        a[i] = {tc, fc};
    }
    RREPS(i, 200) RREPS(j, 200){
        cum[i - 1][j - 1] += cum[i - 1][j] + cum[i][j - 1] - cum[i][j] ;
    }
    /*REP(i, 20){
        REP(j, 20) cout << cum[i + 90][j + 90] << " "; cout << endl;
    }*/
    ll res = 0;
    REP(i, n){
        ll k = -a[i].first, t = -a[i].second; 
        res += cum[k + 100][t + 100];
        if(a[i].first >= 0 and a[i].second >= 0) res--;
    }
    print(res / 2);
}

Measured memory_bytes: 4976