source_code: import java.io.*;
  import java.util.*;
  
  public class Main implements Runnable {
  
  	public void _main() throws IOException {
  		int n = nextInt();
  		int even = 0, odd = 0, atEven = -1, atOdd = -1;
  		for (int i = 0; i < n; i++) {
  			if (nextInt() % 2 == 0) {
  				atEven = i;
  				++even;
  			}
  			else {
  				atOdd = i;
  				++odd;
  			}
  		}
  		if (odd == 1)
  			out.print(atOdd + 1);
  		else
  			out.print(atEven + 1);
  	}
  
  	private BufferedReader in;
  	private PrintWriter out;
  	private StringTokenizer st;
  
  	private String next() throws IOException {
  		while (st == null || !st.hasMoreTokens()) {
  			String rl = in.readLine();
  			if (rl == null)
  				return null;
  			st = new StringTokenizer(rl);
  		}
  		return st.nextToken();
  	}
  
  	private int nextInt() throws IOException {
  		return Integer.parseInt(next());
  	}
  
  	private long nextLong() throws IOException {
  		return Long.parseLong(next());
  	}
  
  	private double nextDouble() throws IOException {
  		return Double.parseDouble(next());
  	}
  
  	public static void main(String[] args) {
  		new Thread(new Main()).start();
  	}
  
  	public void run() {
  		try {
  			in = new BufferedReader(new InputStreamReader(System.in));
  			out = new PrintWriter(System.out);
  
  			_main();
  
  			out.close();
  		} catch (Exception e) {
  			e.printStackTrace();
  			System.exit(202);
  		}
  	}
  
  }
  