import os


TRACE = os.environ.get("TRACEPRISM_RECORD") == "1"
if TRACE:
    from traceprism import record
hp="HAPPY"

def solve() -> None:
    n=int(input())
    S=input()
    ans=0
    for i in range(n-5-4):
        if S[i:i+5]=="HAPPY":
            ans+=1
    for i in range(5):
        ans += 1 if S[n-5+i]!=hp[i] else 0
    print(ans)

if __name__ == "__main__":
    solve()