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

using ll = long long;
[[maybe_unused]] constexpr ll INF = (1LL << 60) - 1;

void solve() {
    ll n, a, b;
    cin >> n >> a >> b;
    for (ll i = 0; i < n; ++i) {
        ll p;
        cin >> p;
        if (p == 1) --a;
        if (p == 2) --b;
        if (p == 3) --a, --b;
        if (a < 0 || b < 0) {
            cout << i + 1 << "\n";
            return;
        }
    }
    cout << -1 << "\n";
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    ll t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}