N = int(input())
S = list(input())

ans = 0

H = "HAPPY"
for i in range(5):
    if S[N-5+i] != H[i]:
        S[N-5+i] = H[i]
        ans += 1

for i in range(N-5):
    if S[i:i+5] == list(H):
        ans += 1
        S[i] = "*"

print(ans)