Python代码

a=int(input())
def trans(n):#进制转换
    x=a
    arr=[]
    while x>=n:
        arr.append(x%n)
        x//=n
    arr.append(x)
    arr=arr[::-1]
    return sum(arr)
res=0
for i in range(2,a):
    res+=trans(i)
def gcd(a,b):
    r=1
    while r!=0:
        r=a%b
        a=b
        b=r
    return a
q=max(res,a-2)
w=min(res,a-2)
c=gcd(q,w)
x=res//c
y=(a-2)//c
print(f'{x}/{y}')