ZCO Wormholes (C++) HELP NEEDED

Hey, so whenever I execute my code I end up with 0 as an output. This is the link for the problem that I am trying to solve. I went about writing the code in several loops.
https://www.codechef.com/ZCOPRAC/problems/ZCO12002

n x y are the 3 starting numbers. The next few lines create vectors which store the input.
I then introduced a for loop to run through each contest timings and find the best/shortest times for each contest. Inside that loop, I have 2 other loops to find the optimal times before the contest and after the contest. And at the end of the loop, I stored the minimum value in btotal and provided that as output. But I can’t seem to get the code to work.

The code is as follows :

enter code here
#include <bits/stdc++.h>

typedef long long ll;

 using namespace std;

int main()

{

ll n,x,y;
ll btotal;
cin>>n;
cin>>x;
cin>>y;

vector<ll> sequence;
sequence.reserve(2*n);
copy_n(istream_iterator<ll>(cin),2*n, back_inserter(sequence));

vector<ll> vin;
vin.reserve(x);
copy_n(istream_iterator<ll>(cin),x, back_inserter(vin));

vector<ll> win;
win.reserve(y);
copy_n(istream_iterator<ll>(cin),y, back_inserter(win));

sort(win.begin(),win.end());
sort(vin.begin(),vin.end());

    //to find smallest time for one event:
   for (ll k=0;k<n;k++)
   {	

	
ll bestl,bestr=100000;

for(ll l=0;l<x;l++)
{
			
	if(sequence[2*k]>vin[l])
	{
	ll bestl = sequence[2*k]-vin[l];
	}
	else if(sequence[2*k]== vin[l])
	{
	ll bestl = 0;
	break;
	}
	else
	{
	break;
	}
	
	
}
for(ll m=0;m<y;m++){
	
	if(sequence[(2*k)+1]<win[m])
	{
	ll bestr = win[m]-sequence[(2*k)+1];
	
	}
	else if(sequence[(2*k)+1]== win[m])
	{
	ll bestr = 0;
	break;
	}
	else
	{
		break;
	}

}

ll total = sequence[(2*k)+1]-sequence[(2*k)]+bestl+bestr+1;
ll btotal = min(total,btotal);
if(k==n-1)
{
	cout<<btotal;
}
else{
continue;
}

   }



  }
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