import java.util.Arrays;
import java.util.Scanner;

public class HelloWorld {

	    public static void main(String[] args) throws Exception {

	    	Scanner sc = new Scanner(System.in);
	    	int n = sc.nextInt();
	    	int[] ai = new int[n];
	    	for (int i = 0; i < n; i ++) {
	    		ai[i] = sc.nextInt();
	    	}
	    	sc.close();

	    	Arrays.sort(ai);
	    	int count = 1;
	    	int mod = ai[0] % 2;
	    	for (int i = 1; i < n; i ++ ) {

	    		if (ai[i] % 2 != mod && ai[i] - 1 <= ai[i - 1]) {
	    			count = 2;
	    		}
	    		mod = ai[i] % 2;
	    	}

	    	System.out.println(count);
	    	}

	    }