source_code: import java.io.*;
  import java.util.*;
  
  public class a implements Runnable {
  
  	private void solve() throws IOException {
  		int n = nextInt();
  		int oddcnt = 0, evencnt = 0;
  		int odd = 0, even = 0;
  		for (int i = 0; i < n; i++) {
  			int a = nextInt();
  			if (a % 2 == 0) {
  				even = i + 1;
  				evencnt++;
  			} else {
  				odd = i + 1;
  				oddcnt++;
  			}
  		}
  		if (oddcnt == 1) {
  			System.out.println(odd);
  		} else {
  			System.out.println(even);
  		}
  	}
  
  	public static void main(String[] args) {
  		new Thread(new a()).start();
  	}
  
  	BufferedReader br;
  	StringTokenizer st;
  	PrintWriter out;
  	boolean eof = false;
  
  	public void run() {
  		Locale.setDefault(Locale.US);
  		try {
  			br = new BufferedReader(new InputStreamReader(System.in));
  			out = new PrintWriter(System.out);
  			solve();
  			out.close();
  		} catch (Throwable e) {
  			e.printStackTrace();
  			System.exit(239);
  		}
  	}
  
  	String nextToken() {
  		while (st == null || !st.hasMoreTokens()) {
  			try {
  				st = new StringTokenizer(br.readLine());
  			} catch (Exception e) {
  				eof = true;
  				return "0";
  			}
  		}
  		return st.nextToken();
  	}
  
  	int nextInt() {
  		return Integer.parseInt(nextToken());
  	}
  
  	long nextLong() {
  		return Long.parseLong(nextToken());
  	}
  
  	double nextDouble() {
  		return Double.parseDouble(nextToken());
  	}
  }