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).
#print(" ".join(map(str, r)))
n = int(input())

a = []

a = [[0] * n for i in range(n)]

for i in range(len(a)):
    for j in range(len(a[i])):
        if i % 2 == 0:
            if j % 2 == 0:
                a[i][j] = "C"
            else:
                a[i][j] = "."
        else:
            if j % 2 !=0:
                a[i][j] = "C"
            else:
                a[i][j] = "."

count = 0
for z in a:
    for u in z:
        if u == "C":
            count+=1

print (count)
for e in a:
    print(" ".join(map(str, e)))



