题解 | Hello World for U

def U(s, n):
    n1 = n2  = n // 3
    r = n % 3
    if r == 0:
        n1 -= 1
        n2 -= 1
    n3 = n - 2 * n1
    m1 = s[:n1]
    m3 = s[n1:n3+n1]
    m2 = s[n3+n1:n]
    c = 0
    i = 1
    for _ in range(n1):
        print(m1[c], end='')
        for _ in range(n3-2):
            print(' ', end='')
   
        print(m2[-i])
        i += 1
        c += 1
    print(m3)

    

while True:
    try:
        s = input()
        n = len(s)
        U(s, n)
    except:
        break