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

#define int long long
#define rep(i, n) for (int i = 0; i < (int) (n); i++)
#define reps(i, n) for (int i = 1; i <= (int) (n); i++)
#define all(x) (x).begin(), (x).end()
#define uniq(x) (x).erase(unique(all(x)), (x).end())
#define bit(n) (1LL << (n))
#define cdiv(a, b) (((a) - 1) / (b) + 1)
#define dump(x) cerr << #x " = " << (x) << endl
using vint = vector<int>;
using vvint = vector<vint>;
using pint = pair<int, int>;
using vpint = vector<pint>;
template<typename T> using priority_queue_rev = priority_queue<T, vector<T>, greater<T>>;
constexpr double PI = 3.1415926535897932384626433832795028;
constexpr int DY[9] = {0, 1, 0, -1, 1, 1, -1, -1, 0};
constexpr int DX[9] = {1, 0, -1, 0, 1, -1, -1, 1, 0};
int gcd(int a, int b) {
    while (b) { swap(a %= b, b); }
    return a;
}
int lcm(int a, int b) { return a / gcd(a, b) * b; }
int sign(int x) { return (x > 0) - (x < 0); }
template<typename T> void fin(T mes) {
    cout << mes << endl;
    exit(0);
}
template<typename T, typename U> bool chmax(T &a, const U &b) {
    if (a < b) {
        a = b;
        return true;
    }
    return false;
}
template<typename T, typename U> bool chmin(T &a, const U &b) {
    if (b < a) {
        a = b;
        return true;
    }
    return false;
}
template<typename T, typename U> ostream &operator<<(ostream &os, const pair<T, U> &rhs) {
    os << "(" << rhs.first << ", " << rhs.second << ")";
    return os;
}
template<typename T> ostream &operator<<(ostream &os, const vector<T> &rhs) {
    os << "{";
    for (auto itr = rhs.begin(); itr != rhs.end(); itr++) {
        os << *itr << (next(itr) != rhs.end() ? ", " : "");
    }
    os << "}";
    return os;
}
template<typename T> ostream &operator<<(ostream &os, const deque<T> &rhs) {
    os << "{";
    for (auto itr = rhs.begin(); itr != rhs.end(); itr++) {
        os << *itr << (next(itr) != rhs.end() ? ", " : "");
    }
    os << "}";
    return os;
}
template<typename T> ostream &operator<<(ostream &os, const set<T> &rhs) {
    os << "{";
    for (auto itr = rhs.begin(); itr != rhs.end(); itr++) {
        os << *itr << (next(itr) != rhs.end() ? ", " : "");
    }
    os << "}";
    return os;
}
template<typename T, typename U> ostream &operator<<(ostream &os, const map<T, U> &rhs) {
    os << "{";
    for (auto itr = rhs.begin(); itr != rhs.end(); itr++) {
        os << *itr << (next(itr) != rhs.end() ? ", " : "");
    }
    os << "}";
    return os;
}
struct setup {
    static constexpr int PREC = 20;
    setup() {
        cout << fixed << setprecision(PREC);
        cerr << fixed << setprecision(PREC);
    };
} setup;

int N;
string a[220000];
int mp[220][220];
int pos[220000], two[220000], five[220000];
int get(int y, int x) {
    return mp[y + 100][x + 100];
}
signed main() {
    cin >> N;
    rep(i, N) { cin >> a[i]; }
    rep(i, N) {
        pos[i] = a[i].find('.');
        if (pos[i] == -1) { pos[i] = a[i].length(); }
        else { a[i].erase(pos[i], 1); }
        pos[i] = a[i].length() - pos[i];
        int x = 0, v = 1;
        for (int j = a[i].length() - 1; j >= 0; j--) {
            x += v * (a[i][j] - '0');
            v *= 10;
        }
        while (x % 2 == 0) { x /= 2, two[i]++; }
        while (x % 5 == 0) { x /= 5, five[i]++; }
        mp[pos[i] - two[i] + 100][pos[i] - five[i] + 100]++;
    }
    rep(i, 200) {
        rep(j, 200) {
            mp[i][j + 1] += mp[i][j];
        }
    }
    rep(i, 200) {
        rep(j, 200) {
            mp[i + 1][j] += mp[i][j];
        }
    }
    int ans = 0;
    rep(i, N) {
        ans += get(two[i] - pos[i], five[i] - pos[i]);
        if (two[i] - pos[i] >= 0 && five[i] - pos[i] >= 0) { ans--; }
    }
    ans /= 2;
    cout << ans << endl;
}

Measured memory_bytes: 15532