#include <bits/stdc++.h>
 
using namespace std;
 
int main()
{
	vector<int> v{0,1,2,3,4,5};
	auto it=v.begin()+3;
	cout<<*it<<"\n";
	v.erase(it);
	cout<<(it==v.begin()+3)<<"\n";
	cout<<*it<<"\n";
}