def main():
    # Read in the information about the set of problems
    proposed, used = map(int, input().split())

    # Store difficulties in a set to remove duplicates
    difficulties = set(int(input().strip()) for _ in range(proposed))

    # We will either have enough difficulties for each problem or the set of 
    # unique difficulties will limit us    
    ans = min(len(difficulties), used)

    # Print the number of unique difficultes computed
    print(ans)

# Entry point for the main function
if __name__ == "__main__":
    main()