#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
using namespace std;


int main(){
    int n,A,B,p,count = 0;
    cin >> n;
    cin >> A >> B;

    while(A >= 0 && B >= 0 && count < n) {
        cin >> p;
        if(p == 1){
            A--;
        } else if(p == 2) {
            B--;
        } else {
            A--;
            B--;
        }
        count++;
    }
    if(n == count) {
    cout <<  -1 << endl;
    } else {
    cout << count << endl;
    }
    return 0;
}