fn main() {
    std::io::stdin().read_line(&mut String::new()).ok();
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).ok();
    let s: Vec<char> = s.trim().chars().collect();

    let mut n = 0;
    for i in 0..s.len() {
        for d in 1.. {
            let j = i + d;
            let k = j + d;
            if k >= s.len() {
                break;
            }
            if s[i] == 'U' && s[j] == 'M' && s[k] == 'G' {
                n += 1;
            }
        }
    }

    println!("{n}");
}