object main{
  object Solver extends Solvable with InputReader{
    def solve(){
      val n = getInt() - 1
      val m = getInt()
      val a = Array(0, 0, 0)
      a(n) = 1

      for(_ <- 1 to m){
        val p = getInt() - 1
        val q = getInt() - 1
        val t = a(p); a(p) = a(q); a(q) = t
      }

      println(a.indexOf(1) + 1)
    }
  }

  // TEMPLATE ------------------------

  def main(args: Array[String]){
    Solver.solve()
  }

  trait Solvable{
    def solve()
  }

  trait InputReader{
    import java.io._
    import java.util._
    protected val stream = System.in
    private val reader = new BufferedReader(new InputStreamReader(stream))
    private var tokenizer = new StringTokenizer(reader.readLine())

    def getStr(): String = {
      while(!tokenizer.hasMoreTokens())
        tokenizer = new StringTokenizer(reader.readLine())
      tokenizer.nextToken()
    }

    def getInt(): Int = getStr().toInt
    def getLong(): Long = getStr().toLong
    def getDouble(): Double = getStr().toDouble
  }
}