出现玄学错误，每次都只输出上次算的结果

#include<bits/stdc++.h>
using namespace std;
int main()
{
	ofstream pyf("gaojing.py");
	pyf<<"with open(\".\\\\input.txt\", \"r+\", encoding=\"utf-8\") as f:\n\
	a, b = map(int, f.read().split())\n\
with open(\".\\\\output.txt\", \"w+\", encoding=\"utf-8\") as f:\n\
	f.write(str(a + b))";
	string a, b, ans;
	cin>>a>>b;
	ofstream inf("input.txt");
	inf<<a<<" "<<b;
	system("start python gaojing.py");
	freopen("output.txt", "r", stdin);
	cin>>ans;
	cout<<ans;
}