#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
  int n, a, b;
  cin >> n >> a >> b;
  for (int i = 1; i <= n; ++i)
  {
    int p;
    cin >> p;
    if (p == 1)
    {
      if (a <= 0)
      {
        cout << i << endl;
        return 0;
      }
      --a;
    }
    if (p == 2)
    {
      if (b <= 0)
      {
        cout << i << endl;
        return 0;
      }
      --b;
    }
    if (p == 3)
    {
      if (a <= 0 || b <= 0)
      {
        cout << i << endl;
        return 0;
      }
      --a;
      --b;
    }
  }
  cout << -1 << endl;
}