#include <bits/stdc++.h>
#include <math.h>
//in the name of god,aka allah
//**gray sety orz**
using namespace std;
#define pi pair<int , int>
#define pii pair<long long , pair<long long , long long>>
const int maxm = 3e5 + 5;
const long long mod = 1e9 + 7 ;
typedef long long ll;
ll n,m;
bool isval(int mid){
//cout << mid <<" " << mid*mid-mid <<endl;
if (((mid-1)*mid)/2 < m) return 0;
return 1;
}
int darage[maxm];
ll ss;
bool mm;
pi pedaret[maxm*2];
int rp[maxm*2];
pi w[maxm];
//ll rw[maxm][maxm];
bool cmp(pi x , pi y){
return max(x.first,x.second)>max(y.first,y.second);
}
void build(int v=1 , int l=1 , int r=m+1){
if(r-l==1){ rp[v] = 0, pedaret[v]={darage[l],l}; return; }
int mid = (l+r)/2;
build(v*2,l,mid) , build(v*2+1,mid,r);
rp[v]=rp[v*2]+rp[v*2+1];
pedaret[v]=max(pedaret[v*2],pedaret[v*2+1]);
}
void shift(int id , int v=1 , int l=1 , int r=m+1){
if(r-l==1){ rp[v] = 1 , pedaret[v] = {-1 , l}; return; }
int mid=(l+r)/2;
if(id<mid) shift(id , v*2 , l , mid);
else shift(id , v*2+1 , mid , r);
rp[v] = rp[v*2] + rp[v*2+1];
pedaret[v] = max(pedaret[v*2] , pedaret[v*2+1]);
}
int upd(int x , int v=1 , int l=1 , int r=m+1){
if(r-l<=1) return l;
int mid = (l+r)/2;
if(pedaret[v*2+1].first>=x) return upd(x,v*2+1,mid,r);
else return upd(x,v*2,l,mid);
}
int get(int lx , int rx , int v=1 , int l=1 , int r=m+1){
if(r<=lx||rx<=l) return 0;
if(lx<=l&&r<=rx) return rp[v];
int mid = (l+r)/2;
return get(lx,rx,v*2,l,mid)+get(lx,rx,v*2+1,mid,r);
}
map<ll,ll> mp;
int main(){
ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
cin >>n>>m;
for (int i=1; i<=n; i++) cin>>w[i].first>>w[i].second;
sort(w+1,w+n+1,cmp);
for (int i=1; i<=m; i++) cin>>darage[i];
build();
//cout<<55;
for (int i=1; i<=n; i++){
mm = 0;
if (w[i].second>w[i].first) swap(w[i].first,w[i].second) , mm = 1;
while (pedaret[1].first>=w[i].first) shift(pedaret[1].second);
//cout<<<69;
if (pedaret[1].first>=w[i].second){//cout<<44<<endl;
//cout<<get(upd(w[i].second),m+1)<<endl;
if (get(upd(w[i].second),m+1)%2) ss+=w[i].second;
else ss+=w[i].first;
}
//cout<<73;
else ss+=((mm)?((rp[1]%2)?w[i].first:w[i].second):(((rp[1]%2)?w[i].second:w[i].first)));
//cout<<i<<endl;
}
cout<<ss;
}
