384A Coder.cpp

#include<bits/stdc++.h>

using namespace std;

int main(){
    float n;
    cin >> n;
    cout << ceil(n*n/2) << endl;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<n;j++)
        {
            if((i+j)%2==0)
            {
                cout << "C";
            }
            else
            {
                cout << ".";
            }
        }
        cout << "\n";
    }

    return 0;
}