#include<bits/stdc++.h>
#include<fstream>
#pragma GCC optimize("Ofast,O3,unroll-loops")
#pragma GCC target("avx2")
using namespace std;
//ifstream fin("FEEDING.INP");
//ofstream fout("FEEDING.OUT");
#define sz(a) (int)a.size()
#define ll long long
#define pb push_back
#define forr(i, a, b) for(int i = a; i < b; i++)
#define dorr(i, a, b) for(int i = a; i >= b; i--)
#define ld long double
#define vt vector
#include<fstream>
#define fi first
#define se second
#define pll pair<ll, ll>
#define pii pair<int, int>
const int mxn = 6e5, base = 74;
const ll p = 31, mod = 1e9 + 7;
int n, k;
int st[4 * mxn + 1], bit[mxn + 1];
void upd(int nd, int l, int r, int id, int v){
if(id < l || id > r)return;
if(l == r){
st[nd] = max(st[nd], v);
return;
}
int mid = (l + r) >> 1;
upd(nd << 1, l, mid, id, v); upd(nd << 1 | 1, mid + 1, r, id, v);
st[nd] = max(st[nd << 1], st[nd << 1 | 1]);
}
int get(int nd, int l, int r, int ql, int qr){
if(ql > r || qr < l)return(0);
if(ql <= l && qr >= r)return(st[nd]);
int mid = (l + r) >> 1;
return(max(get(nd << 1, l, mid, ql, qr), get(nd << 1 | 1, mid + 1, r, ql, qr)));
}
vt<int>comp;
void updbit(int p, int v){
while(p <= sz(comp)){
bit[p] += v; p += p & (-p);
}
}
int getbit(int p){
int ans = 0;
while(p){
ans += bit[p]; p -= p & (-p);
}
return(ans);
}
int find(int x){
return(lower_bound(comp.begin(), comp.end(), x) - comp.begin() + 1);
}
vt<int>q[mxn + 1];
ll a[mxn + 1], b[mxn + 1], c[mxn + 1];
signed main()
{
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
cin >> n >> k;
for(int i = 1; i <= n; i++){
cin >> a[i] >> b[i]; comp.pb(a[i]); comp.pb(b[i]);
}
for(int i = 1; i <= k; i++){
cin >> c[i]; comp.pb(c[i]);
}
sort(comp.begin(), comp.end());
for(int i = 1; i <= k; i++){
upd(1, 1, sz(comp), find(c[i]), i);
}
ll ans = 0;
for(int i = 1; i <= n; i++){
int mn = find(min(a[i], b[i])), mx = find(max(a[i], b[i]));
if(mn == mx){
ans += comp[mn - 1];
continue;
}
int mxid = get(1, 1, sz(comp), mn, mx - 1);
//cout << i << " " << mxid << "\n";
q[mxid].pb(i);
}
for(int i = k; i >= 1; i--){
for(auto j: q[i]){
int mx = find(max(a[j], b[j]));
ll turn = getbit(sz(comp)) - getbit(mx - 1);
//cout << i << " " << j << " " << turn << "\n";
if(turn & 1){
ans += min(a[j], b[j]);
}else{
ans += max(a[j], b[j]);
}
}
updbit(find(c[i]), 1);
}
for(auto i: q[0]){
int mx = find(max(a[i], b[i]));
int turn = getbit(sz(comp)) - getbit(mx - 1);
if(turn % 2 == 0)ans += a[i];
else ans += b[i];
}
cout << ans;
return(0);
}
