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

const int max_n = 100000;

int main(){
    int n, a, b;
    cin >> n >> a >> b;
    vector<int> p(n);
    rep(i,n) cin >> p[i];

    // 制約
    assert(1<=n && n<=max_n);
    assert(1<=a && a<=max_n);
    assert(1<=b && b<=max_n);
    rep(i,n) assert(1<=p[i] && p[i]<=3);

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

}