#include <iostream>
#include <cstdint>

using namespace std;

uint64_t m[1<<25];
int main(void)
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n,a;
  cin>>n;
  a=-n;
  for ( int x;cin>>x; )
  {
    int i=x>>5;
    int sw=x*2&62;
    int c=(m[i]>>sw)&3;
    a+=(9>>(2-c))&3;
    m[i]^=((uint64_t)13>>(c*2)&3)<<sw;
  }
  cout<<a;
}