BaekJoon | 골뱅이 찍기 - ㅁ.py

n = int(input())
for i in range(n):
    print('@'*(n*5))
for j in range(3*n):
    print('@'*n + ' '*(3*n) + '@'*n)
for k in range(n):
    print('@'*(n*5))