#include <bits/stdc++.h>
using namespace std;

#define rep(i, a, b) for (int i = a; i < b; i++)
using ll = long long;

int main(){
	int n, a, b;
	cin >> n >> a >> b;;
	rep(i, 0, n) {
		int p;
		cin >> p;
		if(p == 1) {
			a--;	
		}
		else if(p == 2) {
			b--;
		}
		else {
			a--;
			b--;
		}
		if(a < 0 ||  b < 0)  {
			cout << i + 1 << endl;
			return 0;
		}
	}
	cout << -1 << endl;
}