program main
	implicit none
    integer(8)::len1,a,b,c,i,nmax,nmin
    character(10**5+1)::s
    read(*,*) s
    a=0
    b=0
    c=0
    len1=len_trim(s)
    do i=1,len1
    	if(s(i:i)=='a')then
        	a=a+1
        else if (s(i:i)=='b')then
        	b=b+1
        else
        	c=c+1
        end if
    end do
    nmax=max(a,max(b,c))
    nmin=min(a,min(b,c))
    if(nmax-nmin<=1)then
    	write(*,*) 'Yes'
    else 
    	write(*,*)'No'
    end if
    stop
end program main
    	