from math import ceil
n,k=map(int,input().split())
m=ceil(n/k)
print(m)
grid = [[0]*m for i in range(m)]
y=[0]*m
x=[0]*m
for i in range(m):
    for j in range(m):
        if y[i]<k and x[j]<k:
            grid[i][j]=1
            y[i]+=1
            x[j]+=1
for i in grid:
    for j in i:
        print('.' if j ==0 else '#',end='')
    print()