A, B, S = map(int, input().split())
ans = 0
if A < S and abs(A-S) > abs(B-S):
    # print('B root')
    if A == 0:
        ans += 1
    ans += abs(B-S) + abs(A-S) + A
else:
    # print('A root')
    ans = abs(A-S) + S
print(ans)