#include <bits/stdc++.h>
#define tt cin.tie(0), cout.tie(0), ios_base::sync_with_stdio(0)
#define fo freopen((NAME+".INP").c_str(), "r", stdin), freopen((NAME+".OUT").c_str(), "w", stdout)
#define ll long long
#define ull unsigned long long
#define i128 __int128
#define db long double
#define sz(a) ((int)(a).size())
#define pb emplace_back
#define pf emplace_front
#define pob pop_back
#define pof pop_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define ins emplace
using namespace std;
const int MOD = 1e9+7, MAXN = 2e5+5;
const string NAME = "";
int n,k,val[MAXN][2],query[MAXN];
pair<int,int> p[MAXN];
set<pair<int,int>> s;
ll rs=0;
void compress(){
vector<int> v;
for(int i = 1; i<=n; ++i)
v.pb(p[i].fi), v.pb(p[i].se);
for(int i = 1; i<=k; ++i)
v.pb(query[i]);
sort(v.begin(),v.end()), v.resize(unique(v.begin(),v.end())-v.begin());
for(int i = 1; i<=n; ++i){
p[i].fi=lb(v.begin(),v.end(),p[i].fi)-v.begin()+1;
p[i].se=lb(v.begin(),v.end(),p[i].se)-v.begin()+1;
}
for(int i = 1; i<=k; ++i)
query[i]=lb(v.begin(),v.end(),query[i])-v.begin()+1;
}
int sgtpos[MAXN*12];
void updatepos(int id, int l, int r, int pos, int val){
if(pos<l||r<pos) return;
if(l==r){
sgtpos[id]=val;
return;
}
int mid=(l+r)>>1;
updatepos(id<<1,l,mid,pos,val);
updatepos(id<<1|1,mid+1,r,pos,val);
sgtpos[id]=max(sgtpos[id<<1],sgtpos[id<<1|1]);
}
int getpos(int id, int l, int r, int u, int v){
if(v<l||r<u||u>v) return 0;
if(u<=l&&r<=v) return sgtpos[id];
int mid=(l+r)>>1;
return max(getpos(id<<1,l,mid,u,v),getpos(id<<1|1,mid+1,r,u,v));
}
int bit[MAXN*3];
void update(int pos, int val, int N){
while(pos<=N) bit[pos]+=val, pos+=pos&-pos;
}
int getsum(int pos){
int rs=0;
while(pos>0) rs+=bit[pos], pos-=pos&-pos;
return rs;
}
int main()
{
tt;
if(fopen((NAME + ".INP").c_str(), "r")) fo;
cin >> n >> k;
for(int i = 1; i<=n; ++i)
cin >> p[i].fi >> p[i].se, val[i][0]=p[i].fi, val[i][1]=p[i].se;
for(int i = 1; i<=k; ++i)
cin >> query[i];
compress();
int N=2*n+k;
for(int i = 1; i<=k; ++i)
updatepos(1,1,N,query[i],i);
for(int i = 1; i<=n; ++i){
int MIN=min(p[i].fi,p[i].se),MAX=max(p[i].fi,p[i].se);
s.ins(k-getpos(1,1,N,MIN,MAX-1)+1,i);
}
int j=1;
for(pair<int,int> a : s){
while(j<a.fi) update(query[k+1-j++],1,N);
int MAX=max(p[a.se].fi,p[a.se].se), larger=getsum(N)-getsum(MAX-1);
if(a.fi<=k){
if(p[a.se].fi==MAX) rs+=val[a.se][larger&1];
else rs+=val[a.se][(larger&1)^1];
}else rs+=val[a.se][larger&1];
}
cout << rs;
}
