fn main() {
    let mut checksum = 0;

    "N66555 G1 X131.338 Y133.349 E0.0091".chars().for_each(|c| {
        let mut buf = [0u8; 4];
        c.encode_utf8(&mut buf).bytes().for_each(|b| checksum ^= b);
    });

    println!("{}", checksum);
}