题解 | 特殊的科学计数法

import sys

n = input().strip()
length = len(n)
k = length - 1 

first = int(n[0])  
second = int(n[1])  
third = int(n[2])  # 判断进位

if third >= 5:
    second += 1

if second == 10:
    first += 1
    second = 0

if first == 10:
    first = 1
    second = 0
    k += 1

print(f"{first}.{second}*10^{k}")