source_code: import java.util.Scanner;
  import static java.lang.Math.*;
  import static java.lang.Integer.*;
  import static java.lang.Long.*;
  import static java.util.Arrays.*;
  
  public class A {
  
      public static void main(String[] args) {
          Scanner s = new Scanner(System.in);
          while (s.hasNext()) {
              int n = s.nextInt();
              int[] a = new int[n];
              int odd = 0;
              int even = 0;
              int po = -1;
              int ev = -1;
              for(int i=0;i<n;i++){
                  a[i] = s.nextInt();
                  if(a[i] % 2 == 0) {
                      even ++;
                      ev = i + 1;
                  } else {
                      odd++;
                      po = i + 1;
                  }
              }
              if(odd == 1) {
                  System.out.println(po);
              }else{
                  System.out.println(ev);
              }
          }
      }
  }