int main()
{
	int n,a[100],i;
	while(scanf("%d",&n)!=-1)
	{
		for(i=0;i<=n;i++)scanf("%d",&a[i]);
		if(n<=1) puts("YES");
		else if(n>2) puts("NO");
		else if(a[1]*a[1]<4*a[0]*a[2])
		{
			printf("YES\n");	
		}
		else
		{
			printf("NO\n");	
		}	
	}
	return 0;
}