Python解法

def check_prime(n):
    if n == 2:
        return True
    if n==0 or n==1:
        return False
    else:
        for i in range(2,n):
            if n%i == 0:
                return False
        return True
letters = []
letter_number = []
word = input()
for i in list(word):
    if i not in letters:
        letters.append(i)
        letter_number.append(1)
    elif i in letters:
        letter_number[letters.index(i)] += 1
maxn = max(letter_number)
minn = min(letter_number)
if check_prime(maxn-minn):
    print("Lucky Word")
    print(maxn-minn)
else:
    print("No Answer")
    print("0")