#include<bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
#define int long long
#define ordered_set tree<pair<int,int>, null_type,less<pair<int,int>>, rb_tree_tag,tree_order_statistics_node_update>
#define eb emplace_back
#define S second
#define dbg(v) cerr << #v << " = " << v << "\n"
#define F first
#define fall(i,a,n) for(int i=a;i<=n;i++)
#define rfall(i,a,n) for(int i=a;i>=n;i--)
#define pb push_back
#define all(x) x.begin(),x.end()
#define lsb(x) (x & -x)
#define sz(x) (int)x.size()
const int MAXN=6e5+10;
const int MAXL=1e2+10;
const long long inf=1e17;
const int MOD=1e9+7;
typedef pair<int,int> pii;
typedef tuple<int,int,int> trio;
typedef tuple<int,int,int,int> squad;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
struct node{
int mn,sum;
};
map<int,int> mp,rev;
int n,k;
vector<pii> v;
vector<trio>line;
vector<int> q,ord;
node seg[4*MAXN];
node merge(node a,node b){
node c;
c.sum=a.sum+b.sum;
c.mn=min(a.mn,b.mn);
return c;
}
void build(int ind,int l,int r){
if(l==r){
seg[ind].mn=q[l];
seg[ind].sum=1;
return;
}
int m=(l+r)/2;
build(2*ind,l,m); build(2*ind+1,m+1,r);
seg[ind]=merge(seg[2*ind],seg[2*ind+1]);
}
int query(int ind,int l,int r,int val){
if(seg[ind].mn>=val) return -1;
if(l==r) return l;
if(seg[2*ind+1].mn<val) return query(2*ind+1,(l+r)/2+1,r,val);
return query(2*ind,l,(l+r)/2,val);
}
int query2(int ind,int l,int r,int a,int b){
if(a>r || l>b) return 0;
if(a<=l && b>=r) return seg[ind].sum;
int m=(l+r)/2;
return query2(2*ind,l,m,a,b)+query2(2*ind+1,m+1,r,a,b);
}
void updt(int ind,int l,int r,int a){
if(a<l || a>r) return;
if(l==r){
seg[ind].sum=0;
seg[ind].mn=inf;
return;
}
int m=(l+r)/2; updt(2*ind,l,m,a); updt(2*ind+1,m+1,r,a);
seg[ind]=merge(seg[2*ind],seg[2*ind+1]);
}
int32_t main(){
std::ios_base::sync_with_stdio(false);
cin.tie(NULL);
//freopen("threesum.in","r",stdin);
//freopen("threesum.out","w",stdout);
cin>>n>>k;
v.resize(n),q.resize(k);
for(auto &u:v) cin>>u.F>>u.S;
for(auto &u:q) cin>>u;
build(1,0,k-1);
fall(i,0,n-1) line.pb({min(v[i].F,v[i].S),0,i});
fall(i,0,k-1) line.pb({q[i],1,i});
sort(all(line));
int ans=0;
for(auto [a,b,c]:line){
if(!b){
auto [u,j]=v[c];
int x=query(1,0,k-1,max(u,j));
int quan=query2(1,0,k-1,x+1,k-1);
quan%=2;
if(x!=-1 && u<j) swap(u,j);
if(quan) ans+=j;
else ans+=u;
}
else updt(1,0,k-1,c);
}
cout<<ans<<"\n";
}
