#include<iostream>

 #include<vector>

 using namespace std;

 bool isLegal(int i, int j, vector<string> &current)

 {

     int size = current.size();

     int x = i-, y = j;

     while (x >= )

     {

         if (current[x][y] == 'Q')

             return false;

         x--;

     }

     x = i-;

     y = j - ;

     while (x >=  && y >= )

     {

         if (current[x][y] == 'Q')

             return false;

         x--;

         y--;

     }

     x = i - ;

     y = j + ;

     while (x >=  && y < size)

     {

         if (current[x][y] == 'Q')

             return false;

         x--;

         y++;

     }

     return true;

 }

 void getResult(int row, int index, vector<vector<string>> &result, vector<string> &current, int size)

 {

     if (row == size)

         result.push_back(current);

     else

     {

         while (index < size)

         {

             current[row][index] = 'Q';

             if (isLegal(row, index, current))

                 getResult(row + , , result, current, size);

             current[row][index] = '.';

             index++;

         }

     }

 }

 vector<vector<string>> solveNQueens(int n)

 {

     vector<vector<string>> result;

     string s = "";

     for (int i = ; i < n; i++)

         s.push_back('.');

     vector<string> current(n, s);

     getResult(, , result, current, n);

     return result;

 }

 int main()

 {

     vector<vector<string>> result = solveNQueens();

     for (int i = ; i < result.size(); i++)

     {

         for (int j = ; j < result[i].size(); j++)

             cout << result[i][j].c_str() << endl;

         cout << "-_________________________________________-" << endl;

     }

     return ;

 }