#include<bits/stdc++.h>
#define f first
#define int long long
#define s second
using namespace std;
const int N=2e5+5,mod=1e9+7;
int t[N],tree_[N],tree[4*N],a[N],b[N],n,m;
vector<pair<int,int> > q,V;
set<pair<int,int> > s;
void update(int ind){
for(ind;ind>=1;ind-=ind&(-ind)){
tree_[ind]++;
}
}
int getans(int ind){
int pas=0;
for(ind;ind<=m;ind+=ind&(-ind)){
pas+=tree_[ind];
}
return pas;
}
void update(int u,int ind,int l,int r,int val){
if(l>ind || r<ind) return;
if(l==r) {
tree[u]=val;
return;
}
int mid=(l+r)/2;
update(2*u,ind,l,mid,val);
update(2*u+1,ind,mid+1,r,val);
tree[u]=max(tree[2*u],tree[2*u+1]);
}
int getans(int u,int start,int end,int l,int r){
if(l>end || r<start) return 0;
if(start<=l && r<=end) return tree[u];
int mid=(l+r)/2;
return max(getans(2*u,start,end,l,mid),getans(2*u+1,start,end,mid+1,r));
}
main(){
// t=1;
cin>>n>>m;
for(int i=1;i<=n;i++){
cin>>a[i]; cin>>b[i];V.push_back({max(b[i],a[i]),i});
}
for(int i=1;i<=m;i++){
cin>>t[i];
q.push_back({t[i],i});
}
sort(V.rbegin(),V.rend());
sort(q.rbegin(),q.rend());
for(int i=0;i<q.size();i++){
s.insert({q[i].f,i+1});
update(1,i+1,1,m,q[i].s);
}
int l = -1,ans=0;
for(int i=0;i<V.size();i++){
while(l+1<q.size() && q[l+1].f>=V[i].f) l++,update(q[l].s);
int lst = 1;
if(s.upper_bound({min(a[V[i].s],b[V[i].s]),-1})!=s.end() &&(*s.upper_bound({min(a[V[i].s],b[V[i].s]),-1})).s>l+1 ){
lst =getans(1,l+2,(*s.upper_bound({min(a[V[i].s],b[V[i].s]),-1})).s,1,m);
if(a[V[i].s] < b[V[i].s]) swap(a[V[i].s],b[V[i].s]);
}
//cout<<V[i].s<<" "<<lst<<" "<<getans(lst)<<endl;
if(getans(lst)%2) ans+=b[V[i].s];else ans += a[V[i].s];
}
cout<<ans;
}
