_==0 "exec" "awk" "-f" "$0"
function f(h,n,	i,m) {
	m=0; n=n%2==0 ? n/2 : (n+1)/2
	for (i in h) if (h[i]>m) m=h[i]
	return n>=m
}
NR==1{n=$0}NR>1{h[$0]+=1}END{print f(h,n) ? "YES" : "NO"}