#[cfg(debug_assertions)]
const LENGTH: usize = 5;
#[cfg(not(debug_assertions))]
const LENGTH: usize = 3_017_957;

fn main() {
    let mut pointer = 0;
    let mut has_presents = [true; LENGTH];
    let mut next_elf = [0; LENGTH];

    for (idx, val) in next_elf.iter_mut().enumerate() {
        *val = (idx + 1) % LENGTH;
    }

    'outer: loop {
        let mut offset = 1;
        loop {
            let idx = (pointer + offset) % LENGTH;
            if has_presents[idx] {
                has_presents[idx] = false;
                pointer = idx;
                break;
            } else {
                offset += 1;
            }
        }
        let count = has_presents.iter().filter(|b| **b).count();
        println!("{count}");
        if count == 1 {
            let correct_idx = has_presents
                .iter()
                .enumerate()
                .filter(|(_, b)| **b)
                .map(|(i, _)| i)
                .next()
                .unwrap()
                + 1;
            println!("{correct_idx}");
            break 'outer;
        }
    }
}