#include <iostream>
#include <fstream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <algorithm>
#include <complex>
#include <array>
#include <iomanip>
using namespace std;

#define REP(i,n) for(int i=0; i<n; ++i)
#define FOR(i,a,b) for(int i=a; i<=b; ++i)
#define FORR(i,a,b) for (int i=a; i>=b; --i)
#define ALL(c) (c).begin(), (c).end()

typedef long long ll;
typedef vector<int> VI;
typedef vector<ll> VL;
typedef vector<long double> VD;
typedef vector<VI> VVI;
typedef vector<VL> VVL;
typedef vector<VD> VVD;
typedef pair<int,int> P;
typedef pair<ll,ll> PL;

template<typename T> void chmin(T &a, T b) { if (a > b) a = b; }
template<typename T> void chmax(T &a, T b) { if (a < b) a = b; }

int in() { int x; scanf("%d", &x); return x; }
ll lin() { ll x; scanf("%lld", &x); return x; }
#define INF 1LL<<60

int main() {
    int N;
    cin >> N;

    set<ll> numbers; 
    map<ll, ll> map_numbers;
    REP(i, N) {
        ll tmp;
        cin >> tmp;
        numbers.insert(tmp);
        map_numbers[tmp]++;
    }

    ll ans = 0;
    FORR(t, 37, 1) {
        ll x = pow(2, t-1);
        ll y = pow(2, t);

        if(numbers.size() == 0) break;
        ll max = *numbers.rbegin();
        if(max < x) continue;
        
        set<ll> to_remove;
        for(auto a = numbers.rbegin(); a != numbers.rend(); ++a) {
            if(map_numbers[*a]==0) continue;
            if(*a < x) break;
            if(map_numbers[y - *a]>0 && *a != y - *a) {
                ll num_pair = min(map_numbers[*a], map_numbers[y-*a]);
                ans+=num_pair;
                map_numbers[y-*a]-=num_pair;
                map_numbers[*a]-=num_pair;
                if(map_numbers[*a] == 0) 
                    to_remove.insert(*a);
                if(map_numbers[y-*a] == 0)
                    to_remove.insert(y-*a);
            } else if(map_numbers[y - *a]>=2 && *a == y - *a) {
                ll num_pair = map_numbers[*a] / 2;
                ans+=num_pair;
                map_numbers[*a]-=num_pair;
                if(map_numbers[*a] == 0) 
                    to_remove.insert(*a);
            } else {
                map_numbers[*a] = 0;
                to_remove.insert(*a);
            }
        }

        for(ll r: to_remove) {
            numbers.erase(numbers.find(r));
        }
    }

    cout << ans << endl;

    return 0;
}

#include <bits/stdc++.h>
using namespace std;

using ll=long long;
#define rng(i,l,r) for(int i=int(l);i<int(r);i++)
#define rep(i,r) rng(i,0,r)
#define rrng(i,l,r) for(int i=int(r)-1;i>=int(l);i--)
#define rrep(i,r) rrng(i,0,r)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define F first
#define S second
#define bg begin()
#define ed end()
#define all(x) x.bg,x.ed
#define si(x) int(x.size())
#define inf INT_MAX/2-100
#define infl LLONG_MAX/3
#ifdef LOCAL
#define dmp(x) cerr<<__LINE__<<' '<<#x<<' '<<x<<endl
#else
#define dmp(x) void(0)
#endif
 
template<class t,class u>bool chmax(t&a,u b){if(a<b)a=b;return a<b;}
template<class t,class u>bool chmin(t&a,u b){if(b<a)a=b;return b<a;}
 
template<class t>using vc=vector<t>;
template<class t>using vvc=vector<vector<t>>;
 
using pi=pair<int,int>;
using pl=pair<ll,ll>;
using vi=vc<int>;
using vl=vc<ll>;
 
 
ll readl(void){
	ll x;
	cin>>x;
	return x;
}
int readi(void){
	int x;
	cin>>x;
	return x;
}
 
string readstr(){
	string s;
	cin>>s;
	return s;
}
vi readvi(int n,int off=0){
	vi v(n);
	rep(i,n)v[i]=readi(),v[i]+=off;
	return v;
}
 
vl readvl(int n,int off=0){
	vl v(n);
	rep(i,n)v[i]=readl(),v[i]+=off;
	return v;
}
 
template<class t>
void print(t x,int suc=1){
	cout<<x;
	if(suc==1)cout<<"\n";
	if(suc==2)cout<<" ";
}
 
template<class t>
void print(const vc<t>&v,int suc=1){
	rep(i,si(v))print(v[i],i==int(si(v))-1?1:suc);
}
 
template<class t>
bool inc(t a,t b,t c){
	return !(c<b||b<a);
}
 
template<class t>
void compress(vc<t>&v){
	sort(all(v));
	v.erase(unique(all(v)),v.ed);
}
 
template<class t>
int lwb(const vc<t>&v,const t&a){
	return lower_bound(all(v),a)-v.bg;
}
 
template<class t>
struct Compress{
	vc<t>v;
	Compress()=default;
	Compress(const vc<t>&x){
		add(x);
	}
	Compress(const initializer_list<vc<t> >&x){
		for(auto &p:x)add(p);
	}
	void add(const t&x){
		v.eb(x);
	}
	void add(const vc<t>&x){
		copy(all(x),back_inserter(v));
	}
	void build(){
		compress(v);
	}
	int get(const t&x)const{
		return lwb(v,x);
	}
	vc<t>get(const vc<t>&x)const{
		vc<t>res(x);
		for(auto &p:res)p=get(p);
		return res;
	}
	const t &operator[](int x)const{
		return v[x];
	}
	int size(){
		return v.size();
	}
};
void Yes(bool ex=true){
	cout<<"Yes\n";
	if(ex)exit(0);
}
void YES(bool ex=true){
	cout<<"YES\n";
	if(ex)exit(0);
}
void No(bool ex=true){
	cout<<"No\n";
	if(ex)exit(0);
}
void NO(bool ex=true){
	cout<<"NO\n";
	if(ex)exit(0);
}
void orYes(bool x,bool ex=true){
	if(x)Yes(ex);
	else No(ex);
}
void orYES(bool x,bool ex=true){
	if(x)YES(ex);
	else NO(ex);
}
void Possible(bool ex=true){
	cout<<"Possible\n";
	if(ex)exit(0);
}
void POSSIBLE(bool ex=true){
	cout<<"POSSIBLE\n";
	if(ex)exit(0);
}
void Impossible(bool ex=true){
	cout<<"Impossible\n";
	if(ex)exit(0);
}
void IMPOSSIBLE(bool ex=true){
	cout<<"IMPOSSIBLE\n";
	if(ex)exit(0);
}
void orPossible(bool x,bool ex=true){
	if(x)Possible(ex);
	else Impossible(ex);
}
void orPOSSIBLE(bool x,bool ex=true){
	if(x)POSSIBLE(ex);
	else IMPOSSIBLE(ex);
}
ll n,m,vis[100005],ans,e,o,s,r;
vl g[100005];
bool dfs(int v,int k){
	bool res=true;
	vis[v]=k;
	s++;
	for(auto &i:g[v]){
		if(vis[i]==0){
			res&=dfs(i,k*-1);
		}else if(vis[i]==k){
			res=false;
		}
	}
	return res;
}
int main(void){
	cin.tie(0);
	ios::sync_with_stdio(0);
	cin>>n>>m;
	rep(i,m){
		ll a,b;
		cin>>a>>b;
		g[--a].pb(--b);
		g[b].pb(a);
	}
	fill(vis,vis+n,0);
	r=n;
	rep(i,n){
		if(vis[i]==0){
			s=0;
			bool bd=dfs(i,1);
			if(s==1)ans+=r*2LL-1LL,r--;
			else if(bd)e++;
			else o++;
		}
	}
	ans+=o*o;
	ans+=e*o*2LL;
	ans+=e*e*2LL;
	print(ans);
}