// Arup Guha
// 6/30/2013
// Solution to 2012 MCPC Problem G: Jugglefest

import java.util.*;

public class g {

	public static void main(String[] args) {

		Scanner stdin = new Scanner(System.in);
		int n = stdin.nextInt();

		// Go through each case.
		while (n != 0) {

			// Store cycle values.
			int[] cycle = new int[n];
			for (int i=0; i<n; i++)
				cycle[i] = stdin.nextInt();

			// Set up simulation.
			char[] output = new char[20];
			Arrays.fill(output, ' ');
			char curLet = 'A';
			boolean crash = false;

			// Fill in each juggle spot.
			for (int i=0; i<output.length; i++) {

				// There is already a ball here, don't add a new one.
				if (output[i] != ' ') continue;

				// Loop this ball all the way through the array.
				int skipVal = cycle[i%n];
				
				// Notice how skipVal changes because of which slot the next ball lands...
				for (int j=i; j<output.length; j+= skipVal) {
					
					// This is a conflict, since another ball is already here.
					if (output[j] != ' ') {
						crash = true;
						break;
					}
					
					// Place and update how long this ball will be in the air.
					output[j] = curLet;
					skipVal = cycle[j%n];
				}

				// If this happens, no need to continue.
				if (crash) break;
				curLet++;
			}

			// Output the result.
			if (crash)
				System.out.println("CRASH");
			else
				System.out.println(new String(output));

			// Go to the next case.
			n = stdin.nextInt();
		}

	}
}