while (cin >> n >> a >> b){ for (int i = 1, j = 1; i <= n; i += 2, j++){ int x = n / 2 + 1, y = x; x -= j - 1; y -= j - 1; char c = j % 2 == 1 ? a : b; for (int k = 1; k <= i; k++){ tmp[x + k - 1][y] = c; tmp[x][y + k - 1] = c; tmp[x + i - 1][y + k - 1] = c; tmp[x + k - 1][y + i - 1] = c; } }