#include "bits/stdc++.h" //#include "atcoder/all" using namespace std; //using namespace atcoder; //using mint = modint1000000007; //const int mod = 1000000007; //using mint = modint998244353; //const int mod = 998244353; //const int INF = 1e9; //const long long LINF = 1e18; #define rep(i, n) for (int i = 0; i < (n); ++i) #define rep2(i,l,r)for(int i=(l);i<(r);++i) #define rrep(i, n) for (int i = (n-1); i >= 0; --i) #define rrep2(i,l,r)for(int i=(r-1);i>=(l);--i) #define all(x) (x).begin(),(x).end() #define allR(x) (x).rbegin(),(x).rend() #define endl "\n" int main() { ios::sync_with_stdio(false); cin.tie(nullptr); int H, W, X; cin >> H >> W >> X; if (X % 4 != ((H - 1) + (W - 1)) % 4) { cout << -1 << endl; return 0; } int min = H - 1 + W - 1; int max = ((H + 1) / 2 * (W + 1) / 2) * 2; if ((3 == H % 4) && (3 == W % 4)) { max -= 2; } if ((X < min) || (max < X)) { cout << -1 << endl; return 0; } if ((3 == H % 4) && (3 == W % 4)) { //別処理を書く vectorS(H); rep(i, H) { rep(j, W) { if ((0 == j % 2) || (0 == i)) { S[i] += '.'; } else { S[i] += '#'; } } } int zan = (X - (H - 1) - (W - 1)) / 4; int max1line = (H - 1) / 2; rep(i, (W - 1) / 4) { if (zan > max1line) { S[0][4 * i + 1] = '#'; S[max1line * 2][4 * i + 1] = '.'; zan -= max1line; } else { S[0][4 * i + 1] = '#'; S[zan * 2][4 * i + 1] = '.'; zan = 0; } } rep(i, zan) { S[H - 2 - 4 * i][W - 1] = '#'; S[H - 1 - 4 * i][W - 2] = '.'; S[H - 3 - 4 * i][W - 2] = '.'; S[H - 4 - 4 * i][W - 3] = '#'; } rep(i, H) { cout << S[i] << endl; } return 0; } //通常ケース bool cross = false; if (3 == W % 4) { swap(H, W); cross = true; } vectorS(H); rep(i, H) { rep(j, W) { if ((0 == j % 2) || (0 == i)) { S[i] += '.'; } else { S[i] += '#'; } } } int zan = (X - (H - 1) - (W - 1)) / 4; int max1line = (H - 1) / 2; rep(i, (W - 1) / 4) { if (zan > max1line) { S[0][4 * i + 1] = '#'; S[max1line * 2][4 * i + 1] = '.'; zan -= max1line; } else { S[0][2 * i + 1] = '#'; S[zan * 2][2 * i + 1] = '.'; zan = 0; } } if (cross) { rep(i, W) { rep(j, H) { cout << S[j][i]; } cout << endl; } } else { rep(i, H) { cout << S[i] << endl; } } return 0; }