object Main {

  def main(args: Array[String]): Unit = {
    val input = io.StdIn.readLine().split(" ")
    val inputList: Array[Int] = input.map(_.toInt)
    val answer = solve(inputList(0), inputList(1), inputList(2))
    println(answer.toString)
  }

  private def solve(a: Int, b: Int, c: Int): Int = {
    if (c - (a - b) <= 0) 0
    else c - (a - b)
  }

}