#include using namespace std; using ll = long long; using ld = long double; using VI = vector; using VL = vector; using VS = vector; template using PQ = priority_queue, greater>; using graph = vector; template using w_graph = vector>>; #define FOR(i,a,n) for(int i=(a);i<(n);++i) #define eFOR(i,a,n) for(int i=(a);i<=(n);++i) #define rFOR(i,a,n) for(int i=(n)-1;i>=(a);--i) #define erFOR(i,a,n) for(int i=(n);i>=(a);--i) #define SORT(a) sort(a.begin(),a.end()) #define rSORT(a) sort(a.rbegin(),a.rend()) #define fSORT(a,f) sort(a.begin(),a.end(),f) #define all(a) a.begin(),a.end() #define out(y,x) ((y)<0||h<=(y)||(x)<0||w<=(x)) #define tp(a,i) get(a) #ifdef _DEBUG #define line cout << "-----------------------------\n" #define stop system("pause") #endif constexpr ll INF = 1000000000; constexpr ll LLINF = 1LL << 60; constexpr ll mod = 1000000007; constexpr ll MOD = 998244353; constexpr ld eps = 1e-10; constexpr ld pi = 3.1415926535897932; templateinline bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; }return false; } templateinline bool chmin(T& a, const T& b) { if (a > b) { a = b; return true; }return false; } inline void init() { cin.tie(nullptr); cout.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } templateinline istream& operator>>(istream& is, vector& v) { for (auto& a : v)is >> a; return is; } templateinline istream& operator>>(istream& is, pair& p) { is >> p.first >> p.second; return is; } templateinline vector vec(size_t a) { return vector(a); } templateinline vector defvec(T def, size_t a) { return vector(a, def); } templateinline auto vec(size_t a, Ts... ts) { return vector(ts...))>(a, vec(ts...)); } templateinline auto defvec(T def, size_t a, Ts... ts) { return vector(def, ts...))>(a, defvec(def, ts...)); } templateinline void print(const T& a) { cout << a << "\n"; } templateinline void print(const T& a, const Ts&... ts) { cout << a << " "; print(ts...); } templateinline void print(const vector& v) { for (int i = 0; i < v.size(); ++i)cout << v[i] << (i == v.size() - 1 ? "\n" : " "); } templateinline void print(const vector>& v) { for (auto& a : v)print(a); } inline string reversed(const string& s) { string t = s; reverse(all(t)); return t; } templateinline T sum(const vector& a, int l, int r) { return a[r] - (l == 0 ? 0 : a[l - 1]); } templateinline void END(T s) { print(s); exit(0); } void END() { exit(0); } bool solve(int h, int w, int d, VS& s) { s = VS(h, string(w, '#')); FOR(i, 0, h - 1)FOR(j, 0, w)if (i % 2 == 0 && j % 2 == 0)s[i][j] = '.'; s[h - 1] = string(w, '.'); auto v = vec(h, w); int y = 0, x = 0; bool r = 1; if ((h - 1 - y) + (w - 1 - x) > d)return false; while ((h - 1 - y) + (w - 1 - x) <= d) { v[y][x] = true; if (y == h - 1 && x == w - 1) { if (d > 0)return false; else break; } if (r) { if (x == w - 1) { s[y + 1][x] = '.'; y += 2; r ^= 1; } else { s[y][x + 1] = '.'; x += 2; } } else { if (x == 0) { s[y + 1][x] = '.'; y += 2; r ^= 1; } else { if ((h - 1 - y) + (w - 1 - (x - 2)) > d - 2) { s[y + 1][x] = '.'; y += 2; v[y][x] = true; while (x < w - 1) { s[y][x + 1] = '.'; x += 2; v[y][x] = true; } while (y < h - 1) { s[y + 1][x] = '.'; y += 2; v[y][x] = true; } break; } s[y][x - 1] = '.'; x -= 2; } } d -= 2; } for (int j = 0; j < w - 1; j += 2) { int y = h - 1; while (!v[y - 2][j]) { s[y - 1][j] = '.'; y -= 2; } } return true; } uint32_t rnd() { static uint32_t val = 2718281828ul; val ^= val << 13; val ^= val >> 17; val ^= val << 15; return val; } uint32_t rnd(uint32_t max) { return rnd() % max; } int main() { init(); int t = 1; while (t--) { int h, w, d; cin >> h >> w >> d; //int h = rnd(10) * 2 + 3; //int w = rnd(10) * 2 + 3; //int d = 2 + rnd(h * w) / 2 * 2; print(h, w, d); if (d & 1) { print(-1); } if ((h / 2 + w / 2) % 2 != d / 2 % 2) { print(-1); } else { VS s; if (solve(h, w, d, s)) { FOR(i, 0, h)print(s[i]); } else if (solve(w, h, d, s)) { FOR(i, 0, h) { FOR(j, 0, w)cout << s[j][i]; cout << "\n"; } } else print(-1); } } return 0; }