s=gets.chomp.chars
l=[[0,0]]
r=0
s.each do |c|
#  p l
#  p l[-1][1].even?
#  p (c.ord-97+r)%3
  if l[-1][1].even?
    if (c.ord-97+r)%3==0
      l << [l[-1][0]-1,l[-1][1]+1]
    elsif (c.ord-97+r)%3==1
      l << [l[-1][0],l[-1][1]+1]
      r=(r+1)%3
    else
      l << [l[-1][0],l[-1][1]-1]
      r=(r-1)%3
    end
  else
    if (c.ord-97+r)%3==0
      l << [l[-1][0]+1,l[-1][1]-1]
    elsif (c.ord-97+r)%3==2
      l << [l[-1][0],l[-1][1]-1]
      r=(r-1)%3
    else
      l << [l[-1][0],l[-1][1]+1]
      r=(r+1)%3
    end
  end
end
#p l
puts l.uniq.size