#[allow(unused_imports)]
use proconio::{
    input,
    marker::{Bytes, Chars, Usize1},
};
fn main() {
    input! {
        n: usize,
        mut a: isize,
        mut b: isize,
        p: [usize; n]
    }
    let mut i = 1;
    loop {
        if i == n {
            println!("-1");
            return;
        }
        match p[i - 1] {
            1 => a -= 1,
            2 => b -= 1,
            _ => {
                a -= 1;
                b -= 1;
            }
        }
        if a < 0 || b < 0 {
            break;
        }
        i += 1;
    }
    println!("{}", i);
}