错的很离谱的代码都能AC

#include <bits/stdc++.h>
using namespace std;
int read()
{
	char c=getchar();
	bool f=0;
	int x;
	for (;c<='0'-1||c>='9'+1;)
	{
		if (c=='-') f=1;
		c=getchar();
	}
	x=0;
	for (;c>='0'&&c<='9';)
	{
		x=x*10+(c-'0');
		c=getchar();
	}
	if (f) x=0-x;
	return x;
}
void write(int x)
{
	if (x<=-1) {putchar('-'); x=0-x;}
	putchar((x%10)+'0');
	if (x>=10) write(x/10);
}
int main()
{
	int m=read(),n=read(),i=read(),ans=0;
	for (i=1;i<=m+n;i++) ans=ans+read();
	ans=ans/2;
	cout<<ans<<endl;
	return 0;
}