I tried so many time until I change `#include<bits/stdc++.h>` to `#include<stdio.h>`.

And then I did a small experience: for the same code,
Visual C++ 2017 -- 612 KB
Visual C 2017 -- 620 KB
GCC 7.1 / Clang++ 4.0.1 -- 652 KB
G++ 7.1 -- 700 KB

Hope it helps~