#include <bits/stdc++.h>
using namespace std;
char BB[1 << 15], *SS = BB, *TT = BB;
inline long long read() {
  long long x = 0;
  int f = 1;
  char ch = getchar();
  for (; !isdigit(ch); ch = getchar())
    if (ch == '-') f = -1;
  for (; isdigit(ch); ch = getchar()) x = x * 10 + (ch ^ 48);
  return x * f;
}
inline void print(long long x) {
  if (x < 0) {
    putchar('-');
    x = -x;
  }
  char ch = x % 10 + '0';
  if (x > 9) print(x / 10);
  putchar(ch);
}
long long mul(long long a, long long b, long long mod) {
  if (b < 0) a = -a, b = -b;
  long long ans = 0;
  while (b) {
    if (b & 1) ans = (ans + a) % mod;
    a = (a + a) % mod, b >>= 1;
  }
  return ans;
}
long long exgcd(long long a, long long b, long long &x, long long &y) {
  if (b == 0) {
    x = 1, y = 0;
    return a;
  }
  long long gcd = exgcd(b, a % b, y, x);
  y -= (a / b) * x;
  return gcd;
}
long long gcd(long long a, long long b) { return b == 0 ? a : gcd(b, a % b); }
const int N = 10010;
long long a[N], b[N];
pair<long long, long long> exCRT(int n) {
  long long x, y;
  long long M = b[1], ans = a[1];
  for (int i = 2; i <= n; i++) {
    long long aa = M, bb = b[i], c = (a[i] - ans % bb + bb) % bb;
    long long gcd = exgcd(aa, bb, x, y), g = b[i] / gcd;
    if (c % gcd) return make_pair(0, -1);
    x = (mul(x, c / gcd, g) + bb) % bb;
    ans += x * M;
    M *= g;
    ans = (ans % M + M) % M;
  }
  return make_pair(M, (ans + M - 1) % M + 1);
}
int main() {
  long long n, m, k, x, y, lcm;
  n = read(), m = read(), k = read();
  for (int i = 1; i <= k; i++) b[i] = read();
  for (int i = 1; i <= k; i++) a[i] = ((b[i] - i + 1) % b[i] + b[i]) % b[i];
  pair<long long, long long> e = exCRT(k);
  x = e.first, y = e.second;
  if (y < 1 || y + k - 1 > m || x > n) {
    puts("NO");
    return 0;
  }
  for (int i = 1; i <= k; i++)
    if (gcd(x, y + i - 1) != b[i]) {
      puts("NO");
      return 0;
    }
  puts("YES");
}
