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

def Im_in_1F(a):
    if a == 0:
        return 2
    elif a == 1:
        return 1
    else:
        return a+1

ans = -1
if s == 1:
    ans = Im_in_1F(a)
else:
    if abs(a-s) <= abs(b-s):
        ans = abs(a-s)+s
    else: # abs(a-s) > abs(b-s)
        pat1 = abs(b-s) + abs(a-s) + a
        pat2 = s + Im_in_1F(a)
        ans = min(pat1, pat2)
print(ans)