#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;


// returns (len_of_cycle, first_in-cycle_index)
template<class S, class F>
std::pair<int, int> detect_cycle(F f, S x) {
    S p = x, q = x;
    int l = 0;
    int ub = 1;
    do {
        if (l == ub) {
            ub <<= 1;
            l = 0;
            p = q;
        }
        q = f(q);
        l++;
    } while(p != q);
    p = q = x;
    for(int it = l; it > 0; it--) q = f(q);
    int m = 0;
    while(p != q) p = f(p), q = f(q), m++;
    return {l, m};
}

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int h, w;
  ll k;
  cin >> h >> w >> k;
  struct S {
    int i, j, d;
    bool operator==(const S& rhs) const {
      return i == rhs.i && j == rhs.j && d == rhs.d;
    }
    bool operator!=(const S& rhs) const {
      return !(*this == rhs);
    }
  };
  auto f = [&](S x) {
    auto [i, j, d] = x;
    int di = 1 - 2 * (d & 1);
    int ni = i + di;
    if (0 <= ni && ni < h) i = ni;
    else d ^= 1;
    int dj = 1 - (d & 2);
    int nj = j + dj;
    if (0 <= nj && nj < w) j = nj;
    else d ^= 2;
    return S{i, j, d};
  };
  S now{0, 0, 0};
  auto [l, m] = detect_cycle(f, now);
  vector<string> s(h, string(w, '.'));
  if (k >= m) {
    k = m + (k - m) % (2 * l);
  }
  rrep(_, k) {
    s[now.i][now.j] ^= '.' ^ '#';
    now = f(now);
  }
  rep(i, h) cout << s[i] << '\n';
}