#include <bits/stdc++.h>
#define REP(i,n,N) for(int i=(n);i<(int)N;i++)
#define p(s) cout<<(s)<<endl
using namespace std;

int main(){
	int X,Y,N;
	cin>>X>>Y>>N;
	int A[100];
	REP(i,0,N) cin>>A[i];
	double x=X*10/36.0;
	double y=Y*10/36.0;
	string ans="YES";
	double xs=0,ym=0;
	REP(i,0,N-1){
		xs=A[i]/x;
		ym=xs*y;
		if(ym>A[i+1]) ans="NO";
	}
	p(ans);
	return 0;
}