N = int(input())
S = list(input())
ans = 0
for i in range(N - 5):
    for j in range(5):
        if S[i + j] != 'HAPPY'[j]:
            break
    else:
        S[i + 4] = '-'
        ans += 1
for j in range(5):
    if S[~j] != 'HAPPY'[~j]:
        ans += 1
print(ans)