source_code: import java.io.*;
  import java.math.*;
  import java.util.*;
  import java.util.List;
  import java.util.Queue;
  import java.awt.*;
  import static java.util.Arrays.fill;
  
  public class Solution implements Runnable {
  
      private BufferedReader br = null;
      private PrintWriter pw = null;
      private StringTokenizer stk = new StringTokenizer("");
  
      public static void main(String[] args) {
          new Thread(new Solution()).run();
      }
  
      public void run() {
          /*
           * try { // br = new BufferedReader(new FileReader("input.txt")); pw =
           * new PrintWriter("output.txt"); } catch (FileNotFoundException e) {
           * e.printStackTrace(); }
           */
          br = new BufferedReader(new InputStreamReader(System.in));
          pw = new PrintWriter(new OutputStreamWriter(System.out));
          solver();
          pw.close();
  
      }
  
      private void nline() {
          try {
              if (!stk.hasMoreTokens())
                  stk = new StringTokenizer(br.readLine());
          } catch (IOException e) {
              throw new RuntimeException("KaVaBUnGO!!!", e);
          }
      }
  
      private String nstr() {
          while (!stk.hasMoreTokens())
              nline();
          return stk.nextToken();
      }
  
      private int ni() {
          return Integer.valueOf(nstr());
  
      }
  
      private double nd() {
          return Double.valueOf(nstr());
  
      }
  
      String nextLine() {
          try {
              return br.readLine();
          } catch (IOException e) {
          }
          return null;
      }
  
      private void solver() {
          int n = ni();
          ArrayList<Integer> ar = new ArrayList<Integer>();
          int sum = 0;
          for (int i = 0; i < n; i++) {
              ar.add(ni() % 2);
              sum += ar.get(i);
          }
          int flag = 0;
          if(sum==1)flag = 1;
              for(int i =0;i<n;i++)if(ar.get(i)==flag)System.out.println(i+1);
          
  
      }
  
      void exit() {
          System.exit(0);
      }
  }
  