def escriu_linia(ne):
    print('*', end='')
    for i in range(ne):
        print(' ', end='')
    print('*')

def tr2(n):
    if n >= 1:
        print('*')
    for i in range(n-2):
        escriu_linia(i)
    if n >= 2:
        print('*'*n)