import sequtils,strutils
var
    A,B,S : int
(A, B, S) = stdin.readline.split.map(parseInt)
if abs(A - S) <= abs(B - S) or S == 1:
    echo abs(A - S) + S
else:
    if A == 0:
        A = 2
    echo abs(B - S) + S + A