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())

ans=n**2
ans=(ans+1)//2
print(ans)

temp1=[]

for i in range(n):
    if i%2==0:
        temp1.append("C")
    else:
        temp1.append(".")

temp2=[]

for i in range(n):
    if i%2==0:
        temp2.append(".")
    else:
        temp2.append("C")

arr=[]

for i in range(n):
    if (i%2==0):
        arr.append(temp1)
    else:
        arr.append(temp2)



def solve(arr):
    for i in range(len(arr)):
        print(arr[i],end='')
    print("")

for i in range(n):
    solve(arr[i])

