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).
#!/usr/bin/env python

import math
import sys
import itertools
import fractions

if __name__ == '__main__':
    wtf = sys.stdin.read()
    wtf = wtf.strip().split('\n')
    n = int(wtf[0])
    ans = []
    for i in range(1, n+1):
        s = ''
        for j in range(1,n+1):
            if j%2!=0:
                if i%2!=0:
                    s += 'C'
                else:
                    s += '.'
            else:
                if i%2!=0:
                    s += '.'
                else:
                    s += 'C'
        ans.append(s)
    q,r = 0,0
    if n%2 == 0:
        q = r = n//2
    else:
        q = n//2
        r = q+1
    print(f'{q**2+r**2}\n'+'\n'.join(ans))
