BeiJing2011 元素

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
typedef long long ll;
const int N = 1050;
template<typename T>
inline void read(T&x)
{
    T f = 1,c = 0;char ch=getchar();
    while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
    while(ch>=‘0‘&&ch<=‘9‘){c=c*10+ch-‘0‘;ch=getchar();}
    x = f*c;
}
int n;
struct Pair
{
    ll x;
    int y;
}p[N];
bool cmp(Pair a,Pair b){return a.y>b.y;}
struct lb
{
    ll c[70];
    bool find(ll k)
    {
        for(int i=63;i>=0;i--)if(k&(1ll<<i))
        {
            if(c[i])k^=c[i];
            else return 1;
        }
        return k!=0;
    }
    void insert(ll k)
    {
        for(int i=63;i>=0;i--)if(k&(1ll<<i))
        {
            if(c[i])k^=c[i];
            else
            {
                c[i]=k;
                break;
            }
        }
    }
}tr;
int main()
{
    read(n);
    for(int i=1;i<=n;i++)
        read(p[i].x),read(p[i].y);
    sort(p+1,p+1+n,cmp);
    ll ans = 0;
    for(int i=1;i<=n;i++)
    {
        if(tr.find(p[i].x))
        {
            tr.insert(p[i].x);
            ans+=p[i].y;
        }
    }
    printf("%lld\n",ans);
    return 0;
}