Iahub likes chess very much. He even invented a new chess piece named Coder. A Coder can move (and attack) one square horizontally or vertically. More precisely, if the Coder is located at position (*x*, *y*), he can move to (or attack) positions (*x* + 1, *y*), (*x*–1, *y*), (*x*, *y* + 1) and (*x*, *y*–1).

Iahub wants to know how many Coders can be placed on an *n* × *n* chessboard, so that no Coder attacks any other Coder.
The first line contains an integer *n* (1 ≤ *n* ≤ 1000).
#include <iostream>
#include <string>
#include <cmath>
#include <cstdlib>
#include <list>
#include<iterator>
#include<vector>
#include<algorithm>
#include<stdio.h>
#include<math.h>
#include <numeric>
#include<sstream>
#include<stdlib.h>
#include <queue>
#include<stack>
#include<set>
#include<map>

//ios_base::sync_with_stdio(0);

using namespace std;

int main(){
    int n;
    char a,b,temp;
    cin>>n;
    if(n%2==0)cout<<(n*n/2)<<endl;
    else cout<<((n*n+1)/2)<<endl;
    a='C';
    b='.';
    for(int i=0;i<n;i++){
        for(int j=0;j<n;j++){
            cout<<a;
            temp=a;
            a=b;
            b=temp;
        }
        if(n%2==0){
            temp=a;
            a=b;
            b=temp;
        }
        cout<<"\n";
    }
}
