#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <atcoder/modint>
using namespace std;
using i32 = int;
using u32 = unsigned int;
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<(int)(n); i++)
const i64 INF = 1001001001001001001;

using Modint = atcoder::static_modint<998244353>;

int main(){
    int H, W; cin >> H >> W;
    i64 K; cin >> K;
    vector<vector<int>> vis(4, vector<int>(H*W));
    vector<pair<int,int>> ord;
    int y=0, x=0, h=1, w=1;
    while(vis[h*2+w][y*W+x] == 0){
        ord.push_back({ y, x });
        vis[h*2+w][y*W+x] = 1;
        if(h){
            if(y == H-1) h = 0; else y++;
        } else {
            if(y == 0) h = 1; else y--;
        }
        if(w){
            if(x == W-1) w = 0; else x++;
        } else {
            if(x == 0) w = 1; else x--;
        }
    }
    i64 f = ord.size();
    rep(i,f) ord.push_back(ord[i]);
    K %= (f*2);
    vector<string> ans;
    rep(y,H) ans.push_back(string(W, '.'));
    rep(i,K) ans[ord[i].first][ord[i].second] ^= ('#' ^ '.');
    rep(y,H) cout << ans[y] << '\n';
    return 0;
}

struct ios_do_not_sync{
    ios_do_not_sync(){
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
    }
} ios_do_not_sync_instance;