You are given three integers A, B and C. Find the minimum number of operations required to make A, B and C all equal by repeatedly performing the following two kinds of operations in any order:    * Choose two among A, B and C, then increase both by 1.   * Choose one among A, B and C, then increase it by 2.  It can be proved that we can always make A, B and C all equal by repeatedly performing these operations.
A = [int(i) for i in input().split()]
A.sort()

if ((A[2]-A[1]) + (A[2]-A[0])) % 2 == 0:
    print(((A[2]-A[1]) + (A[2]-A[0])) / 2)
else:
    print((((A[2]-A[1]) + (A[2]-A[0]) + 1) / 2) + 1)
A = [int(i) for i in input().split()]
A.sort()

if ((A[2]-A[1]) + (A[2]-A[0])) % 2 == 0:
    print(int(((A[2]-A[1]) + (A[2]-A[0])) / 2))
else:
    print(int((((A[2]-A[1]) + (A[2]-A[0]) + 1) / 2) + 1))
