source_code: import java.util.*;
  
  public class A {
  
      int n;
      int[] arr;
      
      void run(){
          Scanner s = new Scanner(System.in);
          n = s.nextInt();
          arr = new int[n];
          int even, odd;
          even = 0;
          odd = 0;
          for (int i = 0; i < n; i++) {
              arr[i] = s.nextInt();
              if(arr[i]%2==0)even++;
              else odd++;
          }
          if(even>odd){
          
              
              for (int i = 0; i < n; i++) {
                  if(arr[i]%2==1){
                      System.out.println(i+1);
                      System.exit(0);
                  }
              }
          }
          
          else{
  
              for (int i = 0; i < n; i++) {
                  if(arr[i]%2==0){
                      System.out.println(i+1);
                      System.exit(0);
                  }
              }
  
          }
          
          
      }
      public static void main(String[] args) {
          new A().run();
      }
  }
  