#define _CRT_SECURE_NO_WARNINGS
#define _SILENCE_CXX17_C_HEADER_DEPRECATION_WARNING
#include <bits/stdc++.h>
using namespace std;
const int N = 205;
char mp[N][N];
int main()
{
    int h, w, n;
    scanf("%d%d%d", &h, &w, &n);
    memset(mp, 0, sizeof(mp));
    for (int i = 0; i < h; i++)
        for (int j = 0; j < w; j++)
            mp[i][j] = '*';
    for (int i = 0; i < h; i++)
        for (int j = i & 1; j < w; j += 2)
            if (n)
            {
                mp[i][j] = '#';
                n--;
            }
            else
                mp[i][j] = '*';
    if (n)
        puts("-1");
    else
        for (int i = 0; i < h; i++)
            puts(mp[i]);
    return 0;
}