#include <bits/stdc++.h>

using namespace std;
using ll = long long;
#define rep(i, s, t) for (ll i = s; i < (ll)(t); i++)
#define all(x) begin(x), end(x)
template <class T> bool chmin(T& x, T y) {
	return x > y ? (x = y, true) : false;
}
template <class T> bool chmax(T& x, T y) {
	return x < y ? (x = y, true) : false;
}

void solve() {
	int n, a, b;
	cin >> n >> a >> b;
	rep(i, 0, n) {
		int p;
		cin >> p;
		a--, b--;
		if (p == 1) b++;
		if (p == 2) a++;
		if (a < 0 || b < 0) {
			cout << i + 1 << '\n';
			return;
		}
	}
	cout << "-1\n";
}

int main() {
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	cout << fixed << setprecision(15);
	int t = 1;
	// cin >> t;
	while (t--) solve();
}