A, B, S = map(int, input().split()) candidates = [] # Check down button scenario if S == 1: # B cannot move down from 1st floor, so A comes cost = abs(A - S) + S candidates.append(cost) else: a_dist = abs(A - S) b_dist = abs(B - S) if a_dist <= b_dist: cost = a_dist + S candidates.append(cost) # Check up button scenario a_dist_up = abs(A - S) b_dist_up = abs(B - S) if a_dist_up <= b_dist_up: cost = a_dist_up + S candidates.append(cost) print(min(candidates))