#t = int(input())
t = 1
for _ in range(t):
  n = int(input())
  s = list(input())
  ha = 'HAPPY'
  ans = 0
  for i in range(-5,0):
    if s[i] != ha[i]:
      ans += 1
      s[i] = ha[i]

  for i in range(n-5):
    if "".join(s[i:i+5]) == 'HAPPY':
      ans += 1
  print(ans)