#include<cstdio>
#include<iostream>
#include<algorithm>
#include<stack>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<set>
using namespace std;
int main(){
    int op;
	cin >> op;
	freopen("rec.in", "w", stdout);
	cout << "0\n";
	fclose(stdout);
	freopen("CON", "w", stdout);
	system("cls");
	cout << "ok" << endl;
    return 0;
}

简化程序