#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define finish(x) return cout << x << endl, 0;
struct fenwick{
int n, fen[600005];
void resize(int _n){
n = _n + 1;
memset(fen, 0, sizeof fen);
}
int query(int ind){
int ans = 0;
while(ind >= 1){
ans += fen[ind];
ind -= ind & -ind;
}
return ans;
}
void update(int ind, ll val){
while(ind <= n){
fen[ind] += val;
ind += ind & -ind;
}
}
int query(int l, int r){
return query(r) - query(l - 1);
}
};
struct segment{
int n, seg[1200000];
void resize(int _n){
n = _n;
memset(seg, -1, sizeof seg);
}
void modify(int p, int val){
for(seg[p += n] = val ; p > 1 ; p >>= 1)
seg[p >> 1] = max(seg[p], seg[p ^ 1]);
}
int query(int l, int r){
r++;
int ret = -1;
for(l += n, r += n ; l < r ; l >>= 1, r >>= 1){
if(l & 1) ret = max(ret, seg[l++]);
if(r & 1) ret = max(ret, seg[--r]);
}
return ret;
}
};
int n, k, x, y, mx;
vector <int> a, b, c;
vector <pair <int, int> > q[200001];
map <int, int> com, decode;
segment seg;
fenwick fen;
int main(){
scanf("%d %d", &n, &k);
for(int i = 0 ; i < n && scanf("%d %d", &x, &y) ; i++)
a.push_back(x), b.push_back(y), com[x] = com[y] = 1;
for(int i = 0 ; i < k && scanf("%d", &x) ; i++)
c.push_back(x), com[x] = 1;
x = 1;
for(auto &i : com) i.second = x++;
for(auto &i : a){
decode[com[i]] = i;
i = com[i];
}
for(auto &i : b){
decode[com[i]] = i;
i = com[i];
}
for(auto &i : c) i = com[i];
mx = 2 * n + k + 1;
seg.resize(mx);
fen.resize(mx);
for(int i = 0 ; i < k ; i++)
seg.modify(c[i], i);
for(int i = 0 ; i < n ; i++){
int ind = seg.query(min(a[i], b[i]), max(a[i], b[i]) - 1);
q[ind + 1].push_back(make_pair(max(a[i], b[i]), i));
if(ind != -1 && b[i] > a[i])
swap(a[i], b[i]);
}
for(int i = k - 1 ; i >= 0 ; i--){
fen.update(c[i], 1);
for(auto &j : q[i]){
int val = fen.query(j.first, mx);
if(val % 2) swap(a[j.second], b[j.second]);
}
}
ll ans = 0;
for(auto &i : a) ans += decode[i];
printf("%lld\n", ans);
return 0;
}
