#include <bits/stdc++.h>
#ifdef LOCAL
#include <debug.hpp>
#else
#define debug(...) void(0)
#endif

using namespace std;

typedef long long ll;
#define all(x) begin(x), end(x)
constexpr int INF = (1 << 30) - 1;
constexpr long long IINF = (1LL << 60) - 1;
constexpr int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};

template <class T> istream& operator>>(istream& is, vector<T>& v) {
    for (auto& x : v) is >> x;
    return is;
}

template <class T> ostream& operator<<(ostream& os, const vector<T>& v) {
    auto sep = "";
    for (const auto& x : v) os << exchange(sep, " ") << x;
    return os;
}

template <class T, class U = T> bool chmin(T& x, U&& y) { return y < x and (x = forward<U>(y), true); }

template <class T, class U = T> bool chmax(T& x, U&& y) { return x < y and (x = forward<U>(y), true); }

template <class T> void mkuni(vector<T>& v) {
    sort(begin(v), end(v));
    v.erase(unique(begin(v), end(v)), end(v));
}

template <class T> int lwb(const vector<T>& v, const T& x) { return lower_bound(begin(v), end(v), x) - begin(v); }

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int H, W;
    ll K;
    cin >> H >> W >> K;
    vector dp(H, vector(W, vector<int>(4, INF)));
    vector color(H, vector<int>(W, 0));
    vector<pair<int, int>> path;
    for (int time = 0, x = 0, y = 0, z = 0; dp[x][y][z] == INF; time++) {
        dp[x][y][z] = time;
        path.emplace_back(x, y);
        color[x][y] ^= 1;
        {
            int nx = x + (z & 1 ? -1 : 1);
            if (0 <= nx and nx < H)
                x = nx;
            else
                z ^= 1;
        }
        {
            int ny = y + (z & 2 ? -1 : 1);
            if (0 <= ny and ny < W)
                y = ny;
            else
                z ^= 2;
        }
    }

    int cycle = path.size();
    if (~(K / cycle) & 1) {
        for (int i = 0; i < H; i++) {
            for (int j = 0; j < W; j++) {
                color[i][j] = 0;
            }
        }
    }
    K %= cycle;
    for (int i = 0; i < K; i++) {
        auto [x, y] = path[i];
        color[x][y] ^= 1;
    }
    for (int i = 0; i < H; i++) {
        for (int j = 0; j < W; j++) cout << (color[i][j] ? '#' : '.');
        cout << '\n';
    }
    return 0;
}