#include<iostream>

#include<cstring>

#include<cstdio>

#include<algorithm>

#define LL long long

using namespace std;

LL n,m,k,a[] = {},b[];

LL gcd(LL a,LL b)

{

    return b?gcd(b,a%b):a;

}

LL e_gcd(LL a,LL b,LL &x,LL &y)

{

    if(!b)

    {

        x = ;

        y = ;

        return a;

    }

    LL ans = e_gcd(b,a%b,x,y),temp = x;

    x = y;

    y = temp-a/b*y;

    return ans;

}

LL CRT(LL *a,LL *m) //方程x%m=a;

{

    LL lcm=,X=m[],Y=a[];

    for(int i=;i<=k;i++)   lcm=lcm/gcd(lcm,m[i])*m[i];

    for(int i=;i<=k;i++)

    {

        LL A=X,B=m[i],d,x,y,c=a[i]-Y;

        d=e_gcd(A,B,x,y);

        if(c%d)return -;

        LL mod=m[i]/d;

        LL K=((x*c/d)%mod+mod)%mod;

        Y=X*K+Y;

        X=X*m[i]/d;

    }

    if(Y==)    return lcm;

    return Y;

}

int main()

{

    scanf("%I64d%I64d%I64d",&n,&m,&k);

    for(int i = ;i <= k;i++)   scanf("%I64d",&b[i]);

    LL x = CRT(a,b);

    if(x > n || x < )

    {

        printf("NO\n");

        return ;

    }

    for(int i = ;i <= k;i++)   a[i] = -i;

    LL y = CRT(a,b);

    if(y+k- > m || y < )

    {

        printf("NO\n");

        return ;

    }

    for(int i = ;i <= k;i++)

    {

        if(gcd(x,y+i-) != b[i])

        {

            printf("NO\n");

            return ;

        }

    }

    printf("YES\n");

    return ;

}