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 ())
a = []
for i in range (n):
    var = []
    if i % 2 == 0:
        for i in range (n):
            if i % 2 == 0:
                var.append ("c")
            else:
                var.append (".")
    else:
        for i in range (n):
            if i % 2:
                var.append ("c")
            else:
                var.append(".")
    a.append (var)
print ((n ** 2 // 2)) if  n % 2 == 0 else print (((n ** 2) // 2) + 1)
for i in a:
    print ("".join (i))