#include <bits/stdc++.h>
using namespace std;
long long n, m, a[10003], c[10003], r[10003];
int k;
long long mul(long long a, long long b, long long mod) {
  long long ans = 0;
  while (b) {
    if (b & 1) ans = (ans + a) % mod;
    b >>= 1;
    a = (a + a) % mod;
  }
  return ans % mod;
}
long long gcd(long long x, long long y) {
  long long r;
  while (y) {
    r = x % y;
    x = y;
    y = r;
  }
  return x;
}
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 t = y;
  y = x - (a / b) * y;
  x = t;
}
long long inv(long long a, long long b) {
  long long x, y;
  exgcd(a, b, x, y);
  return (x % b + b) % b;
}
bool check(long long a1, long long a2, long long r1, long long r2,
           long long &aa, long long &rr) {
  long long c = a2 - a1;
  long long d = gcd(r1, r2);
  if (c % d) return 0;
  c /= d;
  r1 /= d;
  r2 /= d;
  long long x = inv(r1, r2);
  c = (c % r2 + r2) % r2;
  rr = r1 * r2 * d;
  x = mul(x, c, r2);
  x = mul(mul(x, r1, rr), d, rr) + a1;
  aa = (x % rr + rr) % rr;
  return 1;
}
int main() {
  scanf("%I64d%I64d%d", &n, &m, &k);
  for (int i = 1; i <= k; i++) scanf("%I64d", &c[i]);
  long long lcm = c[1] / gcd(c[1], c[2]) * c[2];
  for (int i = 3; i <= k; i++) {
    lcm = lcm / gcd(lcm, c[i]) * c[i];
    if (lcm > n) {
      printf("NO\n");
      return 0;
    }
  }
  for (int i = 1; i <= k; i++) r[i] = c[i], a[i] = c[i] - i + 1;
  long long a1, a2, r1, r2, rr, aa;
  a1 = aa = a[1];
  r1 = rr = r[1];
  for (int i = 2; i <= k; i++) {
    a2 = a[i];
    r2 = r[i];
    if (a2 < 0) a2 = (a2 % r2 + r2) % r2;
    if (!check(a1, a2, r1, r2, aa, rr)) {
      printf("NO\n");
      return 0;
    }
    a1 = aa;
    r1 = rr;
  }
  if (!aa) aa += rr;
  if (aa > m - k + 1) {
    printf("NO\n");
    return 0;
  }
  for (int i = 1; i <= k; i++) {
    long long t = gcd(lcm, aa + i - 1);
    if (t != c[i]) {
      printf("NO\n");
      return 0;
    }
  }
  printf("YES\n");
}
