问题 E: 异或和

#include<iostream>
#include<algorithm>
#include<map>
#include<string> 
#include <math.h> 
#include<memory.h>
#include<cstring>
#include<bits/stdc++.h> 
using namespace std;
typedef long long ll; 
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
    while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
    return x*f;
}
const int INF=0x3f3f3f3f;
const int maxn=1e4+100;
const int maxa=1e9+10;
ll a[maxn];
ll n,x;
void inint(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>x;
        for(int j=0;j<20;j++){
            if(x&1<<j){
                a[j]++;
            }
        }
    }
}
int main(){
    inint();
    ll ans=0;
    for(int i=0;i<20;i++){
        ans+=(n-a[i])*a[i]*(1<<i);
    }
    printf("%lld",ans);
         
}