def solve():
    n = int(input())
    a,b = map(int, input().split())
    p = list(map(int, input().split()))

    for i, pi in enumerate(p):
        needa, needb= 0,0
        if pi==1:
            needa += 1
        elif pi==2:
            needb += 1
        else:
            needa += 1
            needb += 1
        if a-needa>=0 and b-needb>=0:
            a -= needa
            b -= needb
        else:
            print(i+1)
            return
    print(-1)
    return



if __name__ == "__main__":
    solve()