#include <iostream>
#define rep(i, n) for(i = 0; i < n; i++)
using namespace std;

int n, a, b;
int p[100000];

int main() {
	int i;

	cin >> n >> a >> b;
	rep(i, n) cin >> p[i];

	rep(i, n) {
		if (p[i] == 1) a--;
		if (p[i] == 2) b--;
		if (p[i] == 3) { a--; b--; }
		if (a < 0 || b < 0) { cout << i + 1 << endl; return 0; }
	}

	cout << -1 << endl;
	return 0;
}