fn read() -> Vec<usize> {
    use std::io::Read;
    let mut s = String::new();
    std::io::stdin().read_to_string(&mut s).unwrap();
    let mut it = s.trim().split_whitespace();
    let mut next = |l: usize, r: usize| -> usize {
        let v = it.next().unwrap().parse::<usize>().unwrap();
        assert!(l <= v && v <= r);
        v
    };
    let n = next(1, 100);
    let mut a = vec![0; n];
    for a in a.iter_mut() {
        *a = next(1, 10usize.pow(18));
    }
    a
}

fn main() {
    let a = read();
    let shift = (0..).find(|k| a.iter().all(|a| *a >> k & 1 == 0)).unwrap();
    let ans = 1usize << shift;
    println!("{}", ans);
}