#include "gap.h"
#include<bits/stdc++.h>
using namespace std;
long long dfs(long long l, long long r)
{
if (r - l <= 1)
return r - l;
if (r - l == 2)
{
long long tl, tr;
MinMax(l, l + 1, &tl, &tr);
if (tr == l + 1)
return 1;
else
return 2;
}
long long m = (l + r) / 2, ll, lr, rl, rr;
MinMax(l + 1, m, &ll, &lr), MinMax(m + 1, r - 1, &rl, &rr);
int ret;
if (ll == -1 && rr == -1)
ret = r - l;
else if (ll == -1)
ret = max({rl - l, dfs(rl, rr), r - rr});
else if (rr == -1)
ret = max({ll - l, dfs(ll, lr), r - lr});
else
ret = max({ll - l, dfs(ll, lr), rl - lr, dfs(rl, rr), r - rr});
return ret;
}
long long findGap(int T, int N)
{
long long l, r;
MinMax(0, 1000000000000000000, &l, &r);
return dfs(l, r);
}
