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).
n = int(input())

if n % 2:
    print((n**2 + 1) // 2)
    type1 = "C." * (n//2) + "C"
    type2 = ".C" * (n//2) + "."
else:
    print((n**2) // 2)
    type1 = "C." * (n//2)
    type2 = ".C" * (n//2)


for i in range(n):
    print(type2 if i % 2 else type1)

"""
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//                                      //
//      Implemented by brownfox2k6      //
//                                      //
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"""