const SOS_LEN: usize = 3;

fn marsExploration(s: &str) -> i32 {
    (0..s.len())
        .step_by(3)
        .map(|i| {
            s[i..i + 3].bytes()
                .zip([b'S', b'O', b'S'])
                .filter(|&zip| zip.0 != zip.1)
                .count() as i32
        })
        .sum()
}