import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum E = 18;

void main() {
  try {
    for (; ; ) {
      const N = readInt();
      auto A = new string[N];
      foreach (i; 0 .. N) {
        A[i] = readToken();
      }
      
      auto xs = new int[N];
      auto ys = new int[N];
      foreach (i; 0 .. N) {
        string a = A[i];
        if (a[$ - 1] != '.') {
          a ~= '.';
        }
        auto as = a.split(".");
        for (; as[1].length < 9; ) {
          as[1] ~= '0';
        }
        long val;
        val += as[0].to!long;
        val *= 10^^9;
        val += as[1].to!long;
        debug {
          writeln("val = ", val);
        }
        for (; val % 2 == 0; val /= 2) {
          ++xs[i];
        }
        for (; val % 5 == 0; val /= 5) {
          ++ys[i];
        }
      }
      debug {
        writeln("xs = ", xs);
        writeln("ys = ", ys);
      }
      
      auto freq = new long[][](E + 1, E + 1);
      foreach (i; 0 .. N) {
        ++freq[min(xs[i], E)][min(ys[i], E)];
      }
      long ans;
      foreach (x; 0 .. E + 1) foreach (y; 0 .. E + 1) {
        foreach (xx; 0 .. E + 1) foreach (yy; 0 .. E + 1) {
          if (x + xx >= E && y + yy >= E) {
            if ([x, y] == [xx, yy]) {
              ans += freq[x][y] * (freq[x][y] - 1) / 2;
            } else if ([x, y] < [xx, yy]) {
              ans += freq[x][y] * freq[xx][yy];
            }
          }
        }
      }
      writeln(ans);
    }
  } catch (EOFException e) {
  }
}
