#pragma region Macros
#include <bits/stdc++.h>
using namespace std;
template <class T> inline bool chmax(T &a, T b) {
    if(a < b) {
        a = b;
        return 1;
    }
    return 0;
}
template <class T> inline bool chmin(T &a, T b) {
    if(a > b) {
        a = b;
        return 1;
    }
    return 0;
}
#ifdef DEBUG
template <class T, class U>
ostream &operator<<(ostream &os, const pair<T, U> &p) {
    os << '(' << p.first << ',' << p.second << ')';
    return os;
}
template <class T> ostream &operator<<(ostream &os, const vector<T> &v) {
    os << '{';
    for(int i = 0; i < (int)v.size(); i++) {
        if(i) { os << ','; }
        os << v[i];
    }
    os << '}';
    return os;
}
void debugg() { cerr << endl; }
template <class T, class... Args>
void debugg(const T &x, const Args &... args) {
    cerr << " " << x;
    debugg(args...);
}
#define debug(...)                                                             \
    cerr << __LINE__ << " [" << #__VA_ARGS__ << "]: ", debugg(__VA_ARGS__)
#define dump(x) cerr << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif

struct Setup {
    Setup() {
        cin.tie(0);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(15);
    }
} __Setup;

using ll = long long;
#define OVERLOAD3(_1, _2, _3, name, ...) name
#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
#define REP1(i, n) for(int i = 0; i < int(n); i++)
#define REP2(i, a, b) for(int i = (a); i < int(b); i++)
#define REP(...) OVERLOAD3(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define UNIQUE(v) sort(ALL(v)), (v).erase(unique(ALL(v)), (v).end())
#define REVERSE(v) reverse(ALL(v))
#define SZ(v) ((int)(v).size())
const int INF = 1 << 30;
const ll LLINF = 1LL << 60;
constexpr int MOD = 1000000007;
constexpr int MOD2 = 998244353;
const int dx[4] = {1, 0, -1, 0};
const int dy[4] = {0, 1, 0, -1};

void Case(int i) { cout << "Case #" << i << ": "; }
int popcount(int x) { return __builtin_popcount(x); }
ll popcount(ll x) { return __builtin_popcountll(x); }
#pragma endregion Macros

void solve() {
    int H, W;
    cin >> H >> W;
    ll K;
    cin >> K;
    vector seen(H, vector(W, vector<int>(4, -1)));
    vector<tuple<int, int, int>> v;
    // 0 -> 下,右 1 -> 上,左
    int x = 0, y = 0, dir = 0;
    v.emplace_back(x, y, dir);
    seen[x][y][dir] = 0;
    int start = -1;
    while(1) {
        debug(x, y, dir);
        int nx = x + ((dir & 1) ? -1 : 1);
        int ny = y + ((dir >> 1 & 1) ? -1 : 1);
        int ndir = 0;
        if(nx < 0 or nx >= H) {
            nx = x;
            if(!(dir & 1)) ndir |= (1 << 0);
        } else {
            if(dir & 1) ndir |= (1 << 0);
        }
        if(ny < 0 or ny >= W) {
            ny = y;
            if(!(dir >> 1 & 1)) ndir |= (1 << 1);
        } else {
            if(dir >> 1 & 1) ndir |= (1 << 1);
        }
        if(seen[nx][ny][ndir] != -1) {
            start = seen[nx][ny][ndir];
            break;
        }
        seen[nx][ny][ndir] = SZ(v);
        v.emplace_back(nx, ny, ndir);
        x = nx;
        y = ny;
        dir = ndir;
    }
    debug(start, SZ(v));
    int loop_len = SZ(v) - start;

    vector<string> S(H, string(W, '.'));
    REP(i, min(K, (ll)start)) {
        auto [x, y, _] = v[i];
        S[x][y] = (S[x][y] == '.' ? '#' : '.');
    }
    if(K <= start) {
        REP(i, H) cout << S[i] << '\n';
        return;
    }
    K -= start;
    if(K / loop_len > 0) {
        REP(_, (((K / loop_len) & 1) ? 1 : 2)) {
            REP(i, start, SZ(v)) {
                auto [x, y, _] = v[i];
                S[x][y] = (S[x][y] == '.' ? '#' : '.');
            }
        }
    }
    REP(i, start, SZ(v)) {
        auto [x, y, _] = v[i];
        if(i - start < K % loop_len) {
            S[x][y] = (S[x][y] == '.' ? '#' : '.');
        } else break;
    }
    REP(i, H) cout << S[i] << '\n';
}

int main() {
    int T = 1;
    // cin >> T;
    while(T--) solve();
}