7 7 7
1
2
3
4
5
6
7
 4 2 8
1
3
4
2
3
4
1
2
 9 4 9
1
2
3
4
5
6
7
8
9
 7 5 7
1
2
3
4
5
6
7
 15 10 15
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
 4 0 4
1
2
3
4
 12 2 12
1
2
3
4
5
6
7
8
9
10
11
12
 10 2 10
1
2
3
4
5
6
7
8
9
10
 7 4 7
1
2
3
4
5
6
7
 7 3 7
1
2
3
4
5
6
7

XXXXXXX
 ..XX.X.X
 ...X.X.XX
 .X.XXXX
 .X.X.X.X.XXXXXX
 ....
 .........X.X
 .......X.X
 .X.X.XX
 ...X.XX

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


public class p4 {

    public static void main(String[]args)
    {
        Scanner sc = new Scanner(System.in);
        
        long n = sc.nextLong();
        long k = sc.nextLong();
        StringBuilder sb = new StringBuilder();
        int p=sc.nextInt();
        
        boolean start1 = false;
        boolean start2 = false;
        if(k < (n - k))
        {
            start1 = true;
        }
        else
        {
            start2 = true;
        }
        
        for(int i=1;i<=p;i++)
        {
            if(start2)
            {
                if(i%2==1 && i < (2*(n-k)+1))
                    sb.append(".");
                else
                    sb.append("X");
            }
            if(start1)
            {
                if(i <= n-k)
                {
                    sb.append(".");
                }
                else
                {
                    sb.append("X");
                }
            }
        }
        
        System.out.println(sb.toString());
    }
    
    public static void debug(Object... obs)
    {
        System.out.println(Arrays.deepToString(obs));
    }
    
    
}
