# include <iostream>
# include <vector>
# include <algorithm>
using namespace std;
# include "gap.h"
//# include "grader.cpp"
const long long INF=1e18;
const int MAX=2e5+11;
int n;
long long a[MAX];
long long findGap(int T, int _N)
{
n=_N;
if(T==1 or n<=60)
{
long long l=1,r=n;
a[0]=-1;
a[n+1]=INF+1;
while(l<=r)
{
long long mn,mx;
MinMax(a[l-1]+1,a[r+1]-1,&mn,&mx);
a[l]=mn;
a[r]=mx;
l++;
r--;
}
long long ans=0;
for(int i=1;i<n;i++) ans=max(ans,a[i+1]-a[i]);
return ans;
}
long long MN,MX;
MinMax(1LL,(long long)1e18,&MN,&MX);
long long last=0,ans=0;
/*
for(int bit=1;bit<60;bit++)
{
long long mn,mx;
MinMax(last+1,last+(1LL<<bit),&mn,&mx);
if(mn!=-1)
{
last=mn;
break;
}
}
*/
last=MN;
while(true)
{
//cout<<"->"<<last<<"\n";
if(last==MX) break;
for(int bit=1;bit<=60;bit++)
{
long long mn,mx;
long long s=last+1,t=last+(1LL<<bit);
MinMax(s,t,&mn,&mx);
if(mn==-1) continue;
else
{
ans=max(ans,mn-last);
last=mx;
break;
}
}
}
return ans;
}
/*
2 4
2 3 6 8
*/
