N = int(input())
S = list(input())
T = list("HAPPY")

ans = 0
for i in range(5):
	if S[N - 5 + i] != T[i]:
		ans += 1
		S[N - 5 + i] = T[i]
for i in range(N - 5):
	if S[i : i + 5] == T:
		ans += 1
		S[i + 4] = 'Z'
print(ans)