PlatouAT

#include <bits/stdc++.h>
#define maxN 1111115
using namespace std;
int findval(long long pos,long long putere)
{
    if(pos==1)
        return 1;
    if(putere==4)
    {
        if(pos==1) return 1;
        if(pos==2) return 0;
        if(pos==3) return 0;
        if(pos==4) return 1;
    }
    long long aux=putere/4;
    if(1<=pos && pos<=aux)
        return findval(pos,putere/4);
    if(aux<pos && pos<=aux*2)
        return 1-findval(pos-aux,putere/4);
    if(aux*2<pos && pos<=aux*3)
        return 1-findval(pos-2*aux,putere/4);
    if(aux*3<pos && pos<=aux*4)
        return findval(pos-3*aux,putere/4);
}
char caracter(long long n)
{
    char c;
    long long putere=1;
    while(putere<=n)
        putere*=4;
    if(putere==4*n)
        putere/=4;
    int aux=findval(n,putere);
    if(aux==1)
        c='A';
    else c='T';
    return c;
}
inline bool putere(long long x)
{
    return !(x&(x-1));
}
int main()
{
    int n;
    cin>>n;
    char actual,precedent='$';
    long long len=0;
    long long maxx=-1;
    for(int i=1;i<=n;i++)
    {
        long long x;
        cin>>x;
        actual=caracter(x);
        if(actual=='T' && precedent=='T')
            len++;
        else
        {
            if(putere(len+1)&&precedent=='T')
                maxx=max(maxx,len);
            if(actual=='T')
                len=1;
            else len=0;
        }
        precedent=actual;
    }
    if(maxx==-1)
        cout<<"NU EXISTA";
    else
        cout<<maxx;
    return 0;
}