#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

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