import java.util.Scanner
fun max(a:Int, b:Int):Int{
  return if(a<b)b else a
}
fun main(args:Array<String>){
  val reader = Scanner(System.`in`);
  var A = reader.nextInt()
  var B = reader.nextInt()
  var C = reader.nextInt()
  var ans = max(0, C-(A-B))
  println("$ans")
}