def pageCount(n, p):
    # Write your code here
    if (n == 1 or n==p):
        return 0
    if (n % 2 > 0 and p == n-1):
        return 0
    midpage1, midpage2 = int(n/2), int(n/2) + 1
    page_counter = 0
    if (p <= midpage1):
        start = 1
        while (start < p):
            start += 2
            page_counter += 1
    elif (p >= midpage2):
        start = n-1
        if (start==p):
            return 1
        while (start > p):
            start -= 2
            page_counter += 1
    return page_counter