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())
count=0
a=[[0 for _ in range(n)]for _ in range(n)]
print((n*n+1)//2)
for i in range(n):
    for j in range(n):
        if i==2:
            break
        if i==0:
            if j==0 or j%2==0:
                a[i][j]='C'
    
            else:
                a[i][j]='.'
                
        elif i==1:
            if a[i-1][j]!='C':
                a[i][j]='C'
            
            else:
                a[i][j]='.'
                
for i in range(n):
    if i%2!=0:
        print(''.join(a[0]))
    else:
        print(''.join(a[1]))