source_code: import java.io.BufferedReader;
  import java.io.InputStreamReader;
  
  public class A {
      public static void main(String[] args) throws Exception {
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          br.readLine();
          String[] ss = br.readLine().split(" ");
          int n = ss.length;
          int[] a = new int[n];
          for (int i = 0; i < n; ++i)
              a[i] = Integer.parseInt(ss[i]);
          for (int i = 0; i < n; ++i) {
              boolean ok = true;
              for (int j = 0; j < n; ++j)
                  if (j != i && a[j] % 2 == a[i] % 2)
                      ok = false;
              if (ok)
                  System.out.println(i + 1);
          }
      }
  }
  