#include <bits/stdc++.h>
using namespace std;
const int N = 1e4 + 5;
long long a[N], l[N], g[N];
void exgcd(long long a, long long b, long long &x, long long &y) {
  if (!b) {
    x = 1, y = 0;
    return;
  }
  exgcd(b, a % b, x, y);
  int t = x;
  x = y;
  y = t - a / b * y;
}
long long gcd(long long a, long long b) {
  if (!(a % b)) return b;
  return gcd(b, a % b);
}
long long ksc(long long a, long long b, long long p) {
  long long an = 0;
  while (b) {
    if (b & 1) an = (an + a) % p;
    a = (a << 1) % p;
    b >>= 1;
  }
  return an;
}
int main() {
  long long n, m, c = 0, v, u, z;
  int k;
  scanf("%lld%lld%d", &n, &m, &k);
  for (int i = 0; i < k; i++) scanf("%lld", &a[i]);
  l[0] = a[0];
  for (int i = 1; i < k; i++) {
    g[i] = gcd(l[i - 1], a[i]);
    if (n / a[i] < l[i - 1] / g[i]) {
      printf("NO\n");
      return 0;
    }
    l[i] = l[i - 1] * a[i] / g[i];
  }
  for (int i = 1; i < k; i++) {
    if ((c + i) % g[i]) {
      printf("NO\n");
      return 0;
    }
    z = l[i - 1] / g[i];
    exgcd(a[i] / g[i], z, v, u);
    c = ((ksc((v % z + z) % z, (c + i) / g[i] % z, z) * a[i] - i) % l[i] +
         l[i]) %
        l[i];
  }
  if (!c) c = l[k - 1];
  if (c + k <= m + 1) {
    for (int i = 0; i < k; i++)
      if (gcd(c + i, l[k - 1]) != a[i]) {
        printf("NO\n");
        return 0;
      }
    printf("YES\n");
  } else
    printf("NO\n");
}
