source_code: import java.util.Scanner;
  
  
  public class A_IQTest {
  
      static int n;
  
      public static void main(String[] args) {
          Scanner s = new Scanner(System.in);
          n = s.nextInt();
          
          int[] nums = new int[n];
          
          for (int i = 0; i < n; i++) {
              nums[i] = s.nextInt();
          }
          
          
          int ei = -1;
          int oi = -1;
          int ecnt = 0;
          int ocnt = 0;
          for (int i = 0; i < n; i++) {
              if(nums[i] % 2 == 0){
                  ei = i;
                  ecnt++;
              }else{
                  oi = i;
                  ocnt++;
              }
          }
          if(ecnt == 1){
              System.out.println(ei+1);
          }else{
              System.out.println(oi+1);
          }
      }
  
  }
  