n = int(input())
for i in range(1, n + 1):
    for j in range(1, n + 1):
        if i == 1 or i == n:
            print('*', end='')
        else:
            if j == 1 or j == n:
                print('*', end='')
            else:
                print(' ', end='')
    print()

/**************************************************************
	Problem: 1492
	User: admin
	Language: Python
	Result: Accepted
	Time:178 ms
	Memory:34480 kb
****************************************************************/