N = int(input())
A3 = [".##","###","##."]
A4 = ["..##",".###","###.","##.."]
def makeA(n):
    if n==3:return A3
    if n==4:return A4
    B = makeA(n-2)
    C = ["."*(n-2)+"##","."+B[0]+"#"]
    for i in range(2,n-2):
        C.append("."+B[i-1]+".")
    C.append("#"+B[n-3]+".")
    C.append("##"+"."*(n-2))
    return C
An = makeA(N)
for row in An:
    print(row)