#include <bits/stdc++.h>
const int mod = 1e9 + 7;
const int maxn = 2e5 + 5;
const double eps = 1e-6;
using namespace std;
bool eq(const double &a, const double &b) { return fabs(a - b) < eps; }
bool ls(const double &a, const double &b) { return a + eps < b; }
bool le(const double &a, const double &b) { return eq(a, b) || ls(a, b); }
long long gcd(long long a, long long b) { return a == 0 ? b : gcd(b % a, a); };
long long lcm(long long a, long long b) { return a / gcd(a, b) * b; }
long long kpow(long long a, long long b) {
  long long res = 1;
  a %= mod;
  if (b < 0) return 1;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
long long read() {
  long long x = 0, f = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') f = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = x * 10 + ch - '0';
    ch = getchar();
  }
  return x * f;
}
map<int, int> bad, f;
int pre[maxn] = {0}, a[maxn], dp[maxn];
int F(int x) {
  if (f[x]) return f[x];
  int ret = 0, xx = x;
  for (int i = 2; i * i <= xx; ++i) {
    while (xx % i == 0) {
      if (bad[i])
        ret--;
      else
        ret++;
      xx /= i;
    }
  }
  if (xx > 1) {
    if (bad[xx])
      ret--;
    else
      ret++;
  }
  return f[x] = ret;
}
int main() {
  int n, m, x;
  scanf("%d%d", &n, &m);
  for (int i = 1; i < (n + 1); ++i)
    scanf("%d", a + i), pre[i] = gcd(pre[i - 1], a[i]);
  for (int i = 0; i < (m); ++i) scanf("%d", &x), bad[x] = 1;
  int ans = 0;
  dp[0] = ans;
  for (int i = n; i >= (1); --i) {
    if (F(pre[i]) < 0) {
      int p = pre[i];
      for (int j = 1; j < (i + 1); ++j) {
        pre[j] /= p;
        a[j] /= p;
      }
    }
  }
  for (int i = 1; i < (n + 1); ++i) ans += F(a[i]);
  printf("%d\n", ans);
  return 0;
}
