a,b,s=map(int,input().split())
if abs(a-s)<=abs(b-s):
  print(abs(a-s)+s)
else:
  if a==0:
    print(abs(b-s)+s+1)
  elif s==1:
    print(a)
  else:
    print(min(abs(b-s)+abs(a-s)+a,abs(b-s)+s-1+a))