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).
def main():
    lst = ['.' for x in range(0, 500)]
    s = 'C'.join(lst) + 'C'
    lst = ['C' for x in range(0, 500)]
    s_ = '.'.join(lst) + '.'
    
    n = int(input())
    
    if ((n*n) % 2 == 0):
        print((n*n)//2)
    else:
        print((n*n)//2 + 1)
        
    cs = s[:n]
    cs_ = s_[:n]
    flag = True
    for i in range(n):
        if(flag):
            print(cs_)
            flag = False
        else:
            print(cs)
            flag = True
            
if __name__ == '__main__':
    main()
