#include <bits/stdc++.h>
using namespace std;
const long long N = 1e5 + 100;
long long n, m, k, a[N], b[N], c[N];
inline void add(long long &a, long long b, long long mod) {
  a = ((a + b >= mod) ? a + b - mod : a + b);
}
inline long long mul(long long a, long long b, long long mod) {
  long long f = 1;
  if (b < 0) f = mod - 1, b = -b;
  long long ans = 0;
  while (b) {
    if (b & 1) add(ans, a, mod);
    b >>= 1;
    add(a, a, mod);
  }
  ans = ((f == 1) ? ans : mod - ans);
  return ans;
}
inline long long read() {
  long long f = 1, x = 0;
  char s = getchar();
  while (s < '0' || s > '9') {
    if (s == '-') f = -1;
    s = getchar();
  }
  while (s >= '0' && s <= '9') {
    x = x * 10 + s - '0';
    s = getchar();
  }
  return x * f;
}
long long gcd(long long a, long long b) { return (!b) ? a : gcd(b, a % b); }
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);
  long long z = x;
  x = y;
  y = z - (a / b) * y;
}
signed main() {
  n = read();
  m = read();
  k = read();
  for (long long i = 1; i <= k; i++)
    a[i] = read(), b[i] = (1 - i + a[i]) % a[i];
  memcpy(c, a, sizeof(a));
  long long lcm = a[1];
  for (long long i = 2; i <= k; i++) {
    long long g = gcd(lcm, a[i]);
    lcm /= g;
    if (lcm > n / a[i]) {
      printf("NO\n");
      return 0;
    }
    lcm *= a[i];
  }
  for (long long i = 2; i <= k; i++) {
    long long g = gcd(a[i], a[1]);
    if ((b[1] - b[i]) % g != 0) {
      printf("NO\n");
      return 0;
    }
    long long x, y;
    exgcd(a[i] / g, a[1] / g, x, y);
    a[1] = a[1] / gcd(a[1], a[i]) * a[i];
    x = (x % a[1] + a[1]) % a[1];
    x = mul(x, (b[1] - b[i]) / g, a[1]);
    b[1] = (b[i] + mul(x, a[i], a[1])) % a[1];
    b[1] = (b[1] % a[1] + a[1]) % a[1];
  }
  if (b[1] == 0) b[1] = lcm;
  if (b[1] > m - k + 1 || b[1] == 0) {
    printf("NO\n");
    return 0;
  }
  bool bl = 1;
  for (long long i = 1; i <= k; i++) {
    if (gcd(lcm, b[1] + i - 1) != c[i]) bl = 0;
  }
  if (bl)
    printf("YES\n");
  else
    printf("NO\n");
}
