#![allow(non_snake_case)]
#![allow(dead_code, unused_macros)]

use std::process::exit;
#[allow(unused_imports)]
use proconio::{input, marker::Usize1, marker::Chars};
#[allow(unused_imports)]
use itertools::Itertools;

macro_rules! d {
    ( $( $x:expr ),* $(,)? ) => {
        println!(
            concat!( $( stringify!($x), "={:?} " ),* ),
            $( $x ),*
        );
    };
}

fn main() {
    input! {
        N: usize,
        A: i64,
        B: i64,
        P: [i64; N],
    }

    let mut a = A;
    let mut b = B;
    for (i, &p) in P.iter().enumerate() {
        match p {
            1 => {
                a -= 1;
            },
            2 => {
                b -= 1;
            }
            3 => {
                a -= 1;
                b -= 1;
            }
            _ => unreachable!()
        }

        if a < 0 || b < 0 {
            println!("{}", i+1);
            exit(0);
        }
    }

    println!("-1");
}