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).
a = int(input())
if a%2==1:
    print(a*a//2+1)
else:
    print(a*a//2)
ch=["C","."]
fs = [" "]*a
ss = [" "]*a
for i in range(a):
    fs[i] = ch[i%2]
for i in range(a):
    ss[i] = ch[(i+1)%2]
fs = "".join(fs)
ss = "".join(ss)
for i in range(a):
    if i%2 == 0:
        print(fs)
    else:
        print(ss)
