func main()
	var ss: [][]char :: cui@input().split(" ")
	var x: int :: ss[0].toInt(&)
	var y: int :: ss[1].toInt(&)
	var z: int :: ss[2].toInt(&)
	var ans: int :: z - (x <= z ?(1, 0)) - (y <= z ?(1, 0))
	do cui@print("\{ans}\n")
end func