/*************

   CF#338D

   by chty

   2016.11.3

 *************/

 #include<iostream>

 #include<cstdio>

 #include<cstdlib>

 #include<cstring>

 #include<ctime>

 #include<cmath>

 #include<algorithm>

 using namespace std;

 typedef long long ll;

 ll n,m1,K,A,M,ans,lcm(),m[],a[];

 inline ll read()

 {

     ll x=,f=;  char ch=getchar();

     while(!isdigit(ch))  {if(ch=='-')  f=-;  ch=getchar();}

     while(isdigit(ch))  {x=x*+ch-'';  ch=getchar();}

     return x*f;

 }

 ll gcd(ll a,ll b) {return !b?a:gcd(b,a%b);}

 void exgcd(ll a,ll b,ll &g,ll &x,ll &y)

 {

     if(b==)  {x=; y=; g=a; return;}

     exgcd(b,a%b,g,x,y);

     ll t=x;x=y;y=t-a/b*y;

 }

 ll China()

 {

     for(ll i=;i<=K;i++)  a[i]=-i;

     A=a[],M=m[];

     for(ll i=;i<=K;i++)

     {

         ll k,y,da=a[i]-A,g;

         exgcd(M,m[i],g,k,y);

         if(da%g)  return -;

         ll t=m[i]/g;

         k*=da/g;

         k=(k%t+t)%t;

         A+=k*M;

         M=M*m[i]/g;

         A=(A+M)%M;

     }

     return A;

 }

 bool check()

 {

     if(lcm>n)  return ;

     ll ans=China();

     if(ans<)  return ;

     if(ans==)  ans=lcm;

     if(ans+K->m1)  return ;

     for(ll i=;i<=K;i++)  if(gcd(lcm,ans+i-)!=m[i])  return ;

     return ;

 }

 int main()

 {

     //freopen("cin.in","r",stdin);

     //freopen("cout.out","w",stdout);

     n=read();  m1=read();  K=read();

     for(ll i=;i<=K;i++)  m[i]=read();

     for(ll i=;i<=K;i++)

     {

         lcm=lcm/gcd(lcm,m[i])*m[i];

         if(lcm>n) break;

     }

     check()?puts("YES"):puts("NO");

     return ;

 }