#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
#define rc(x) return cout<<x<<endl,0
#define pb push_back
#define mkp make_pair
#define in insert
#define er erase
#define fd find
#define fr first
#define sc second
#define all(x) x.begin(),x.end()
#define lun(x) (int)x.size()
typedef long long ll;
typedef long double ld;
const ll INF=0x3f3f3f3f3f3f3f3f;
const ll llinf=(1LL<<60);
const int inf=(1<<30);
const int nmax=2e5+50;
const ll mod=1e9+7;
using namespace std;
int n,k,i,j,x,mn,mx,a[nmax],b[nmax],q[nmax],st[4*nmax],fw[nmax],sw[nmax],sz;
ll rs;
vector<int>vc;
vector<pair<int,int> >vec[nmax];
void ufw(int i)
{
for(;i>=1;i-=i&(-i))fw[i]++;
}
int qfw(int i)
{
int ans=0;
for(;i<=sz;i+=i&(-i))ans+=fw[i];
return ans;
}
void upd(int nod,int l,int r,int p,int v)
{
if(l==r)
{
st[nod]=v;
return;
}
int mid=(l+r)/2;
if(p<=mid)upd(2*nod,l,mid,p,v);
else upd(2*nod+1,mid+1,r,p,v);
st[nod]=max(st[2*nod],st[2*nod+1]);
}
int qry(int nod,int l,int r,int tl,int tr)
{
if(tr<l || tl>r)return 0;
if(tl<=l && r<=tr)return st[nod];
int mid=(l+r)/2;
return max(qry(2*nod,l,mid,tl,tr),qry(2*nod+1,mid+1,r,tl,tr));
}
int main()
{
//freopen("sol.in","r",stdin);
//freopen("sol.out","w",stdout);
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ios_base::sync_with_stdio(false);cin.tie(0);cerr.tie(0);cout.tie(0);
cin>>n>>k;
for(i=1;i<=n;i++)cin>>a[i]>>b[i];
for(i=1;i<=k;i++)
{
cin>>q[i];
vc.pb(q[i]);
}
sort(all(vc));
vc.resize(unique(all(vc))-vc.begin());
sz=lun(vc);
for(i=1;i<=k;i++)
{
q[i]=lower_bound(all(vc),q[i])-vc.begin()+1;
upd(1,1,sz,q[i],i);
}
for(i=1;i<=n;i++)
{
mn=min(a[i],b[i]),mx=max(a[i],b[i]);
mn=lower_bound(all(vc),mn)-vc.begin()+1;
mx=lower_bound(all(vc),mx)-vc.begin();
x=0;
if(mn<=mx && mx<=sz)x=qry(1,1,sz,mn,mx);
if(x)
{
sw[i]=1;
if(a[i]>b[i])swap(a[i],b[i]);
}
vec[x].pb(mkp(i,mx+1));
}
for(i=k;i>=0;i--)
{
for(j=0;j<lun(vec[i]);j++)sw[vec[i][j].fr]^=(qfw(vec[i][j].sc)&1);
if(i)ufw(q[i]);
}
for(i=1;i<=n;i++)
{
if(sw[i])rs+=1LL*b[i];
else rs+=1LL*a[i];
}
cout<<rs<<endl;
return 0;
}
