source_code: import java.io.BufferedReader;
  import java.io.InputStreamReader;
  import java.util.StringTokenizer;
  
  
  public class Main {
      
      public static void main(String[] args) throws Exception {
          int i,j,k;
          int counter[] = new int[2];
          int a[] = new int[200];
          int needed;
          
          BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
          
          int N = Integer.parseInt(br.readLine());
          StringTokenizer st = new StringTokenizer(br.readLine());
          
          for (i=1;i<=N;i++) {
              a[i] = Integer.parseInt(st.nextToken());
              counter[a[i]%2]++;
          }
          
          if (counter[0] == 1) {
              needed = 0;
          } else {
              needed = 1;
          }
          
          for (i=1;i<=N;i++) {
              if (a[i]%2 == needed) {
                  System.out.println(i);
                  return;
              }
          }
          
      }
  
  }
  