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).
"""
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"""

from math import ceil
n = int(input())
# 3
# C . C
# . C .
# C . C

#4
# C . C .
# . C . C
# C . C .
# . C . C

ind1 = 0
Select1 = 1
Select2 = -1
print(((ceil(n/2))**2) + (ceil((n-1)/2)**2))
if n%2==0:
    s1='C.'*(n//2)
    s2='.C'*(n//2)
    for i in range(n//2):
        print(s1)
        print(s2)
else:
    s1='C.'*((n+1)//2)
    s2='.C'*((n+1)//2)
    for i in range((n+1)//2):
        print(s1[:n])
        print(s2[:n])
"""
for i in range(n):
    while ind1<n:
        Print(Select1)
        Select1*=-1
        ind1+=1
    print()
    ind1=0
    Select1 = Select2
    Select2*=-1
"""







