Write a code to generate a hollow rectangle using stars.

def pattern(r, c):
    for i in range(1, r+1):
        l = []
        if i == 1 or i == r:
            for j in range(c):
                l.append('*')
        else:
            l.append('*')
            for j in range(1, c-1):
                l.append(' ')
            l.append('*')
        print(*l)

r, c = map(int, input().split())
pattern(r, c)