using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static int NN => int.Parse(ReadLine());
    static int[] NList => ReadLine().Split().Select(int.Parse).ToArray();
    public static void Main()
    {
        Solve();
    }
    static void Solve()
    {
        var c = NList;
        var (h, w) = (c[0], c[1]);
        var k = long.Parse(ReadLine());
        var dp = new bool[h][];
        for (var i = 0; i < dp.Length; ++i) dp[i] = new bool[w];

        var rx = 0;
        var ry = 0;
        var dx = 1;
        var dy = 1;
        var time = 0;
        do
        {
            dp[rx][ry] = !dp[rx][ry];
            if (rx + dx < 0 || rx + dx >= h) dx = -dx;
            else rx += dx;
            if (ry + dy < 0 || ry + dy >= w) dy = -dy;
            else ry += dy;
            ++time;
        }
        while (rx != 0 || ry != 0 || dx != 1 || dy != 1);
        k %= time;
        for (var i = 0; i < k; ++i)
        {
            dp[rx][ry] = !dp[rx][ry];
            if (rx + dx < 0 || rx + dx >= h) dx = -dx;
            else rx += dx;
            if (ry + dy < 0 || ry + dy >= w) dy = -dy;
            else ry += dy;
        }
        // WriteLine(time);
        WriteLine(string.Join("\n", dp.Select(di => string.Concat(di.Select(d => d ? '#' : '.')))));
    }
}