#include <iostream>
#include <vector>
using namespace std;
bool isLegal(int row,int col,vector<string> &v,int n)
{
	for(int i=0;i<row;++i)
		if(v[i][col]=='Q') return false;
	for(int i=row-1,j=col-1;i>=0&&j>=0;--i,--j)
		if(v[i][j]=='Q') return false;
	for(int i=row-1,j=col+1;i>=0&&j<n;--i,++j)
		if(v[i][j]=='Q') return false;
	return true;
}
void snqHelp(vector<vector<string>> &res,vector<string> &v,int row,int n)
{
	if(row==n)
	{
		res.push_back(v);
		return;
	}
	for(int col=0;col<n;++col)
	{
		if(isLegal(row,col,v,n))
		{
			v[row][col]='Q';
			snqHelp(res,v,row+1,n);
			v[row][col]='.';
		}
	}
}
vector<vector<string>> solveNQueens(int n)
{
	vector<vector<string>> res;
	vector<string> v(n,string(n,'.'));
	snqHelp(res,v,0,n);
	return res;
}
int main(int argc, char const *argv[])
{
	int n;
	cout<<"input n :";
	cin>>n;
	vector<vector<string>> res=solveNQueens(n);
	for(auto vstr:res)
	{
		for(auto x:vstr)
			cout<<x<<endl;
		string line(2*n,'-');
		cout<<line<<endl;
	}
	cout<<"Total solution :"<<res.size()<<endl;
	return 0;
}