A, B, S = map(int, input().split())


def f(p, a, b):
    if p == 1:
        return abs(1 - a) + 1

    ax = abs(p - a)
    bx = abs(p - b)
    if ax <= bx:
        return ax + p

    return min(bx + p + f(1, a, 1),
               bx + ax + f(a, a, a))


ans = f(S, A, B)
print(ans)