def main():
    N = int(input())
    K = int(input())
    num_list = []
    for n in range(N):
        num_list.append(int(input()))
    #print(num_list)

    sorted_num_list = sorted(num_list)
    print(sorted_num_list[-1] - sorted_num_list[0]) 


if __name__ == '__main__':
    main()