#include <bits/stdc++.h>

using namespace std::literals;

bool solve(std::istream& is, std::ostream& os) {
  int X, Y, K, P;
  is >> X >> Y >> K >> P;
  K = X + Y - K;
  if (Y & 1) {
    P = -P;
  }
  if (K & 1) {
    if (P == 1) {
      return ~Y & 1 || K - 1 <= Y;
    } else {
      return Y & 1 || K <= Y;
    }
  } else {
    P = -P;
    if (P == 1) {
      return !(~Y & 1 || K <= Y);
    } else {
      return !(Y & 1 || K <= Y);
    }
  }
}

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  std::cout << (solve(std::cin, std::cout) ? "Alice\n" : "Bob\n");
}