#include<bits/stdc++.h>
#define allof(a) a.begin(),a.end()
#define int long long
#define fi first
#define se second
#define pb push_back
#define F(i,a,b) for(int i=a;i<=b;i++)
#define D(i,a,b) for(int i=a;i>=b;i--)
#define inf 0x3f3f3f3f3f3f3f3f
#define mn 200001
#define task "kosaraju"
using namespace std;
const int mod= 1e9+7;
typedef pair<int,int> ii;
typedef pair<int,ii> ip;
int n,k;
ii a[mn],t[mn];
struct interval_tree{
#define mid (l+r>>1)
#define lc 2*id,l,mid
#define rc 2*id+1,mid+1,r
int st[4*mn],hi[4*mn];
void update(int id,int l,int r,int i,int val){
if(l==r){
st[id]=1;
hi[id]=val;
return;
}
if(i<=mid)update(lc,i,val);
else update(rc,i,val);
st[id]=st[2*id]+st[2*id+1];
hi[id]=max(hi[2*id],hi[2*id+1]);
}
int getsum(int id,int l,int r,int u,int v){
if(v<l || r<u)return 0;
if(u<=l && r<=v)return st[id];
return getsum(lc,u,v)+getsum(rc,u,v);
}
int getmax(int id,int l,int r,int u,int v){
if(v<l || r<u)return -inf;
if(u<=l && r<=v)return hi[id];
return max(getmax(lc,u,v),getmax(rc,u,v));
}
}st1,st2;
int32_t main()
{
ios::sync_with_stdio(0);
#ifdef _TPR_
freopen("t.inp","r",stdin);
freopen("t.out","w",stdout);
#endif
cin>>n>>k;
F(i,1,n)cin>>a[i].fi>>a[i].se;
sort(a+1,a+n+1,[](const ii& a,const ii& b)
{return max(a.fi,a.se)>max(b.fi,b.se);});
F(i,1,k){
cin>>t[i].fi;t[i].se=i;
}
sort(t+1,t+k+1,[](const ii& a,const ii& b)
{return a.fi<b.fi;});
F(i,1,k)st2.update(1,1,k,i,t[i].se);
int res=0,cur=k;
F(i,1,n){
while(cur && t[cur].fi>=max(a[i].fi,a[i].se)){
st1.update(1,1,k,t[cur].se,1);
cur--;
}
int l=distance(t,lower_bound(t+1,t+k+1,ii(min(a[i].fi,a[i].se),-1)));
int r=distance(t,lower_bound(t+1,t+k+1,ii(max(a[i].fi,a[i].se),-1)));
if(l<r){
int pos=st2.getmax(1,1,k,l,r-1);
if(st1.getsum(1,1,k,pos+1,k)&1)res+=min(a[i].fi,a[i].se);
else res+=max(a[i].fi,a[i].se);
}
else{
if(st1.getsum(1,1,k,1,k)&1)res+=a[i].se;
else res+=a[i].fi;
}
}
cout<<res;
}
