#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, **a, count = 0;
  cin >> n;
  for (int i = 0; i < n; i++) {
    if (i % 2 == 0) {
      for (int j = 0; j < n; j++) {
        if (j % 2 == 0) count++;
      }
    } else {
      for (int j = 0; j < n; j++) {
        if (j % 2 != 0) count++;
      }
    }
  }
  cout << count << "\n";
  for (int i = 0; i < n; i++) {
    if (i % 2 == 0) {
      for (int j = 0; j < n; j++) {
        if (j % 2 == 0) {
          cout << "C";
        } else
          cout << ".";
      }
      cout << "\n";
    } else {
      for (int j = 0; j < n; j++) {
        if (j % 2 == 0)
          cout << ".";
        else {
          cout << "C";
        }
      }
      cout << "\n";
    }
  }
  return 0;
}
