a, b, s = map(int, input().split())

if abs(s - a) <= abs(s - b):
    print(abs(s - a) + s)
elif s == 1:
    print(a)
else:
    ans = abs(s - b)
    if 1 <= a <= s:
        ans += s
    elif a == 0:
        ans += s + 1
    else:
        ans += min(s + abs(a - 1), abs(a - s) + a)
    print(ans)