def main():
    A, B, S = map(int, input().split())
    if abs(S-A) <= abs(S-B) or S == 1:
        print(abs(S-A) + S)
    elif A == 0:
        print(abs(S-B) + (S-1) + 2)
    else:
        print(abs(S-B) + min(abs(S-A), abs(S-1)) + A)


if __name__ == '__main__':
    main()