import scala.io.StdIn

object Main extends App {
  val Array(a, b, c)  = StdIn.readLine().split(" ").map(_.toInt)

  def solve(a: Int, b: Int, c: Int): Int = {
    val d = a - b
    val ans = c - d

    if (ans < 0) 0 else ans
  }

  println(solve(a, b, c))
}
  

