s = STDIN.gets

ans = 0

s.scan(/phn(?:om)+/).each do |t|
  ans += t.length - 3
end

s.gsub!(/phn(?:om)+/, "phn")

if s.include?("h") then
  ans += 1;

  s.gsub!("h", "")
  s.gsub!("e", "h")
end


s.scan(/phn(?:om)+/).each do |t|
  ans += t.length - 3
end

s.gsub!(/phn(?:om)+/, "phn")

if s.include?("h") then
  ans += 1;

  s.gsub!("h", "")
  s.gsub!("e", "h")
end


puts ans