#include <bits/stdc++.h>
using namespace std;

#define rep(i, m, n) for(int(i) = (int)(m); i < (int)(n); ++i)
#define rep2(i, m, n) for(int(i) = (int)(n)-1; i >= (int)(m); --i)
#define REP(i, n) rep(i, 0, n)
#define REP2(i, n) rep2(i, 0, n)
#define all(hoge) (hoge).begin(), (hoge).end()
#define en '\n'
using ll = long long;
using ull = unsigned long long;
template <class T>
using vec = vector<T>;
template <class T>
using vvec = vector<vec<T>>;
typedef pair<ll, ll> P;
using tp = tuple<ll, ll, ll>;
constexpr long long INF = 1LL << 60;
constexpr int INF_INT = 1 << 25;
//constexpr long long MOD = (ll)1e9 + 7;
constexpr long long MOD = 998244353LL;
using ld = long double;
static const ld pi = 3.141592653589793L;
typedef vector<ll> Array;
typedef vector<Array> Matrix;

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;
}

//グラフ関連
struct Edge {
    ll to, cap, rev;
    Edge(ll _to, ll _cap, ll _rev) {
        to = _to;
        cap = _cap;
        rev = _rev;
    }
};
typedef vector<Edge> Edges;
typedef vector<Edges> Graph;

void add_edge(Graph &G, ll from, ll to, ll cap, bool revFlag, ll revCap) {
    G[from].push_back(Edge(to, cap, (ll)G[to].size()));
    if(revFlag)
        G[to].push_back(Edge(from, revCap, (ll)G[from].size() - 1));
}

ll con[15][15][15][15];
ll sum[15][15][16][16];
void solve() {
    ll n;
    cin >> n;
    REP(i, n) {
        string s;
        cin >> s;
        ll m = s.size();
        bool flag = false;
        ll a = 0;
        ll b = 1;
        REP(i, m) {
            if(s[i] == '.') {
                flag = true;
                continue;
            }
            if(flag) {
                b *= 10;
            }
            a *= 10;
            a += s[i] - '0';
        }
        ll g = gcd(a, b);
        a /= g;
        b /= g;

        ll cona2 = 0;
        while(a % 2 == 0 and cona2 < 14) {
            a /= 2;
            cona2++;
        }
        ll cona5 = 0;
        while(a % 5 == 0 and cona5 < 14) {
            a /= 5;
            cona5++;
        }

        ll conb2 = 0;
        while(b % 2 == 0 and conb2 < 14) {
            b /= 2;
            conb2++;
        }
        ll conb5 = 0;
        while(b % 5 == 0 and conb5 < 14) {
            b /= 5;
            conb5++;
        }
        con[cona2][cona5][conb2][conb5]++;
    }

    REP(i, 15) {
        REP(j, 15) {
            REP(k, 15) {
                REP(l, 15) {
                    sum[i][j][k + 1][l + 1] = sum[i][j][k + 1][l] + sum[i][j][k][l + 1] - sum[i][j][k][l] + con[i][j][k][l];
                }
            }
        }
    }

    ll ans = 0;
    REP(i, 15) {
        REP(j, 15) {
            REP(k, 15) {
                REP(l, 15) {
                    if(con[i][j][k][l] == 0)
                        continue;
                    ll tmp = 0;
                    rep(a2, k, 15) {
                        rep(a5, l, 15) {
                            tmp += sum[a2][a5][i + 1][j + 1];
                        }
                    }

                    ans += tmp * con[i][j][k][l];
                    if(i >= k and j >= l and k <= i and l <= j)
                        ans -= con[i][j][k][l];
                }
            }
        }
    }

    cout << ans / 2 << en;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    /*
    ll t;
    cin >> t;
    while(t--)*/
    solve();

    return 0;
}


Measured memory_bytes: 4160