import sys

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

da = abs(s-a)
db = abs(s-b)
come_elevator = "a" if da <= db else "b"
if come_elevator == "a":
    print(da+s)
    exit()
pattern1 = da+a
pattern2 = b+a
out = pattern1 if pattern1 > pattern2 else pattern2

print(out)