source_code: import java.util.Scanner;
  
  public class Solution {
  
      public static void main(String args[]) {
      Scanner scanner = new Scanner(System.in);
      int n = scanner.nextInt();
      int[] arr = new int[n];
      for (int i = 0; i < n; ++i) {
          arr[i] = scanner.nextInt();
      }
      boolean isOdd = false;
      if ((arr[0] % 2 == 0 && arr[1] % 2 == 0) || (arr[0] % 2 == 0 && arr[2] % 2 == 0)
          || (arr[1] % 2 == 0 && arr[2] % 2 == 0)) {
          isOdd = true;
      }
      if (isOdd) {
          for (int i = 0; i < n; ++i) {
          if (arr[i] % 2 == 1) {
              System.out.println(i + 1);
              break;
          }
          }
      } else {
          for (int i = 0; i < n; ++i) {
          if (arr[i] % 2 == 0) {
              System.out.println(i + 1);
              break;
          }
          }
      }
  
      }
  
  }
  