def extract_arguments(fh):
    n, k, a, b = map(int, fh.readline().strip().split())
    x = list(map(int, fh.readline().strip().split()))
    return n, k, a, b, x

# if __name__ == "__main__":
#     input_path = sys.argv[1]
#     with open(input_path, 'r') as fh: 
#     n, k, a, b, x = extract_arguments(fh)
#     f(n, k, a, b, x)