import java.io.*;
import java.util.*;

public class Main {
    private static final boolean N_CASE = false;

    private void solve() {
        int N = sc.nextInt();
        long[] x = new long[N];
        for (int i = 0; i < N; ++i) {
            String s = sc.next();
            int j = 0;
            while (j < s.length() && s.charAt(j) != '.') {
                char c = s.charAt(j);
                x[i] = x[i] * 10 + (c - '0');
                ++j;
            }
            ++j;
            for (int k = 0; k < 9; ++k, ++j) {
                x[i] *= 10;
                if (j < s.length()) {
                    x[i] += (s.charAt(j) - '0');
                }
            }
        }

        int m1 = 20;
        int m2 = 41;
        int[][] cnt = new int[20][41];
        long ans = 0;
        for (int i = 0; i < N; ++i) {
            long t = x[i];
            int c5 = 0;
            while (t % 5 == 0) {
                t /= 5;
                ++c5;
            }

            t = x[i];
            int c2 = 0;
            while (t % 2 == 0) {
                t /= 2;
                ++c2;
            }

            for (int k1 = 0; k1 < m1; ++k1) {
                for (int k2 = 0; k2 < m2; ++k2) {
                    if (k1 + c5 >= 18 && k2 + c2 >= 18) {
                        ans += cnt[k1][k2];
                    }
                }
            }

            ++cnt[c5][c2];
        }

        out.println(ans);
    }

    private void run() {
        int T = N_CASE ? sc.nextInt() : 1;
        for (int t = 0; t < T; ++t) {
            solve();
        }
    }

    private static MyWriter out;
    private static MyScanner sc;

    private static class MyScanner {
        BufferedReader br;
        StringTokenizer st;

        private MyScanner() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            while (st == null || !st.hasMoreElements()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        int[] nextIntArray(int n) {
            int[] a = new int[n];
            for (int i = 0; i < n; i++) {
                a[i] = nextInt();
            }
            return a;
        }

        int[][] nextIntArray(int n, int m) {
            int[][] a = new int[n][m];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    a[i][j] = sc.nextInt();
                }
            }
            return a;
        }

        long[][] nextLongArray(int n, int m) {
            long[][] a = new long[n][m];
            for (int i = 0; i < n; i++) {
                for (int j = 0; j < m; j++) {
                    a[i][j] = nextLong();
                }
            }
            return a;
        }

        List<Integer> nextList(int n) {
            List<Integer> list = new ArrayList<>();
            for (int i = 0; i < n; i++) {
                list.add(nextInt());
            }
            return list;
        }

        List<Long> nextLongList(int n) {
            List<Long> list = new ArrayList<>();
            for (int i = 0; i < n; i++) {
                list.add(nextLong());
            }
            return list;
        }

        char[] nextCharArray(int n) {
            return sc.next().toCharArray();
        }

        char[][] nextCharArray(int n, int m) {
            char[][] c = new char[n][m];
            for (int i = 0; i < n; i++) {
                String s = sc.next();
                for (int j = 0; j < m; j++) {
                    c[i][j] = s.charAt(j);
                }
            }
            return c;
        }
    }

    private static class MyWriter extends PrintWriter {
        private MyWriter(OutputStream outputStream) {
            super(outputStream);
        }

        void printArray(int[] a) {
            for (int i = 0; i < a.length; ++i) {
                print(a[i]);
                print(i == a.length - 1 ? '\n' : ' ');
            }
        }

        void printlnArray(int[] a) {
            for (int v : a) {
                println(v);
            }
        }

        void printList(List<Integer> list) {
            for (int i = 0; i < list.size(); ++i) {
                print(list.get(i));
                print(i == list.size() - 1 ? '\n' : ' ');
            }
        }

        void printlnList(List<Integer> list) {
            list.forEach(this::println);
        }
    }

    private <T> List<List<T>> createGraph(int n) {
        List<List<T>> g = new ArrayList<>();
        for (int i = 0; i < n; ++i) {
            g.add(new ArrayList<>());
        }
        return g;
    }

    public static void main(String[] args) {
        out = new MyWriter(new BufferedOutputStream(System.out));
        sc = new MyScanner();
        new Main().run();
        out.close();
    }
}

Measured memory_bytes: 55696