module Main;

import CPLib.IO;

main: IO ();
main = (
    let n = *read_i;
    let s = (*read_s).get_bytes.pop_back;
    let h = "HAPPY".get_bytes.pop_back;
    let match_at = |i| (
        range(0, 5).check_all(|j| s.@(i + j) == h.@(j))
    );
    let ans = range(0, n-10+1).filter(match_at).get_size;
    let ans = ans + range(0, 5).filter(|j| s.@(n - 5 + j) != h.@(j)).get_size;
    println $ ans.to_string
);