def print_rangoli(size):
    n = size
    l1 = list(map(chr, range(97, 123)))
    x = l1[n-1::-1]+l1[1:n]
    m = len('-'.join(x))
    for i in range(1, n):
        print('-'.join(l1[n-1:n-i:-1]+l1[n-i:n]).center(m, '-'))
    for i in range(n, 0, -1):
        print('-'.join(l1[n-1:n-i:-1]+l1[n-i:n]).center(m, '-'))
