Module a

ABC 375 A - Seats

refs: https://atcoder.jp/contests/abc375/tasks/abc375_a

use proconio::{input, marker::Chars};

fn main() {
    input! {
        n: usize,
        s: Chars,
    }

    let mut ans = 0;
    if s.len() <= 2 {
        println!("0");
        return;
    }

    for i in 0..(n - 2) {
        if (s[i], s[i + 1], s[i + 2]) == ('#', '.', '#') {
            ans += 1;
        }
    }

    println!("{ans}");
}