import java.util.Random;
public class cfg
{
//  str is the string being operated on.
    static String str;
    public static void main(String args[])
    {
    //  We start with the start string.
        str = "S";
        int left = 1;
    //  As long as rules doesn't return 0, we still have more non-terminals.
        while (left == 1)
        {
            left = rules();
        }
    //  Once we're done, print the result.
        System.out.println(str);
    }
    public static int rules()
    {
        Random randomizer = new Random();
        int i, rndm;
    //  We look for each of the non-terminals.  When one is found, it is replaced.
    //  The replacement rule is chosen randomly, with weights to make things interesting.
        i = str.indexOf("S");
        if (i != -1)
        {
            rndm = randomizer.nextInt(9);
            if (rndm == 0)
            {
                str = "";
            }
            else if (rndm <= 5)
            {
                str = str.substring(0,i) + "M" + str.substring(i+1);
            }
            else
            {
                str = str.substring(0,i) + "N" + str.substring(i+1);
            }
            return 1;
        }
        
        i = str.indexOf("M");
        if (i != -1)
        {
            rndm = randomizer.nextInt(6);
            if (rndm == 0)
            {
                str = str.substring(0,i) + "AC" + str.substring(i+1);
            }
            else if (rndm <= 3)
            {
                str = str.substring(0,i) + "AO" + str.substring(i+1);
            }
            else
            {
                str = str.substring(0,i) + "N" + str.substring(i+1);
            }
            return 1;
        }
        
        i = str.indexOf("N");
        if (i != -1)
        {
            rndm = randomizer.nextInt(3);
            if (rndm == 0)
            {
                str = str.substring(0,i) + "BC" + str.substring(i+1);
            }
            else
            {
                str = str.substring(0,i) + "BP" + str.substring(i+1);
            }
            return 1;
        }
        
        i = str.indexOf("O");
        if (i != -1)
        {
            str = str.substring(0,i) + "MC" + str.substring(i+1);
            return 1;
        }
        
        i = str.indexOf("P");
        if (i != -1)
        {
            str = str.substring(0,i) + "NC" + str.substring(i+1);
            return 1;
        }
        
        i = str.indexOf("A");
        if (i != -1)
        {
            str = str.substring(0,i) + "a" + str.substring(i+1);
            return 1;
        }
        
        i = str.indexOf("B");
        if (i != -1)
        {
            str = str.substring(0,i) + "b" + str.substring(i+1);
            return 1;
        }
        
        i = str.indexOf("C");
        if (i != -1)
        {
            str = str.substring(0,i) + "c" + str.substring(i+1);
            return 1;
        }
    //  If there are no more non-terminals, return 0.
        return 0;
    }
}