public class timadaemi{
    public static void main(String[] args){
        int a = Integer.parseInt(args[0]);
        int max = 0;
        int newmax = 0;
        while(!StdIn.isEmpty()){
            int x = StdIn.readInt();
            if((x>max) && (x<a)) {
                max = x;
            }
        }
        System.out.println(max);
    }
}