import java.util.*;
public class Main {
  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      String lo = sc.nextLine();
      int n =Integer.parseInt(lo);
      String l=sc.nextLine();
      int b[] = new int[n];
      //String [] ll=l.split(" ");
      //int a =Integer.parseInt(ll[1]);
      int sum1=0;
    // int sum2=0;
        for(int i=0;i<n;i++){
          String [] ll=l.split(" ");
         
          b[i]=Integer.parseInt(ll[i]);
          sum1=sum1+b[i];
          
    //  System.out.println(l);
  }
  if(sum1%2==0){
             System.out.println("possible");
          }
      
      else{System.out.println("impossible");}
        }
}