#include <bits/stdc++.h>
using namespace std;

#define FOR(i, n, m) for (int i = n; i < (int)m; ++i)
#define REP(i, n) FOR(i, 0, n)
#define REP_1(i, n) for (int i = 1; i <= (int)n; ++i)
#define RFOR(i, n, m) for (int i = (int)n - 1; i >= (int)m; --i)
#define RREP(i, n) RFOR(i, n, 0)
#define RREP_1(i, n) for (int i = (int)n; i >= 1; --i)

#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
#define SIZE(v) (int)v.size()
#define EMPTY(v) v.empty()
#define SORT(v) sort(ALL(v))
#define RSORT(v) sort(RALL(v))
#define REVERSE(v) reverse(ALL(v))
#define UNIQUE(v) (SORT(v), v.erase(unique(ALL(v)), v.end()))

#define PB push_back
#define EB emplace_back
#define MP make_pair

#define YES() cout << "YES\n"
#define NO() cout << "NO\n"
#define Yes() cout << "Yes\n"
#define No() cout << "No\n"
#define YESNO(cond) cout << ((cond) ? "YES" : "NO") << '\n'
#define YesNo(cond) cout << ((cond) ? "Yes" : "No") << '\n'

#define IN(x, a, b) ((a) <= (x) && (x) < (b))
#define BETWEEN(x, a, b) ((a) <= (x) && (x) <= (b))

#define FASTIO()                                                               \
    ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr)
#define PRECISION(n) cout << fixed << setprecision(n)

using P = pair<int, int>;
using ll = long long;
using ull = unsigned long long;
using ld = long double;

template <class T> using min_queue = priority_queue<T, vector<T>, greater<T>>;
template <class T> using max_queue = priority_queue<T>;

constexpr ll INF = 1000000000;
constexpr ll INFL = (ll)1000000000000001000LL;
constexpr ll MOD = 998244353;
constexpr ld PI = 3.141592653589793238462643383279;
constexpr ld EPS = 1e-9;

constexpr int dx4[] = {-1, 1, 0, 0};
constexpr int dy4[] = {0, 0, -1, 1};
constexpr int dx8[] = {0, 1, 1, 1, 0, -1, -1, -1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1};

void solve() {
    int n;
    string s;
    cin >> n >> s;
    int ans = 0;
    if (s[n - 5] != 'H') ans++;
    if (s[n - 4] != 'A') ans++;
    if (s[n - 3] != 'P') ans++;
    if (s[n - 2] != 'P') ans++;
    if (s[n - 1] != 'Y') ans++;
    for (int i = n - 6; i >= 0; i--) {
        if (s.substr(i, 5) != "HAPPY") continue;
        ans++;
    }
    cout << ans << endl;
}

int main() {
    FASTIO();
    int t = 1;
    while (t--) {
        solve();
    }
}