#include <iostream>
#include <vector>
#include <map>
#include <algorithm>
using namespace std;
const int N = (1<<20) + 1;
int A[N], B[N], T[N], idx[N], cnt[N], ft[N], Mx[N<<1], cur;
void insert(int i, int vl, int cur = 1, int st = 1, int en = N){
if (i >= en or i < st)
return;
if (en - st == 1){
Mx[cur] = vl;
return;
}
int lc = cur + cur, rc = lc + 1, mid = (st + en) / 2;
insert(i, vl, lc, st, mid);
insert(i, vl, rc, mid, en);
Mx[cur] = max(Mx[cur], vl);
}
int get(int l, int r, int cur = 1, int st = 1, int en = N){
if (l >= en or r <= st)
return 0;
if (l <= st and r >= en)
return Mx[cur];
int lc = cur + cur, rc = lc + 1, mid = (st + en) / 2;
return max(get(l, r, lc, st, mid), get(l, r, rc, mid, en));
}
void Add(int i){
for (; i; i -= i & -i)
ft[i]++;
}
void get2(int i, int &ans){
for (; i < N; i += i & -i)
ans += ft[i];
}
map<int,int> mp, mp2;
int main(){
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
long long n, q, Ans = 0;
cin>>n>>q;
for (int i=1;i<=n;i++){
cin>>A[i]>>B[i];
mp[A[i]];
mp[B[i]];
}
for (int i=1;i<=q;i++)
cin>>T[i], mp[T[i]];
for (auto [i, j] : mp)
mp2[i] = ++cur;
vector<pair<int,int>> Quer;
for (int i=1;i<=q;i++){
T[i] = mp2[T[i]];
insert(T[i], i);
Quer.push_back({T[i], i + N});
}
for (int i=1;i<=n;i++){
int a = mp2[min(A[i], B[i])], b = mp2[max(A[i], B[i])];
idx[i] = get(a, b);
Quer.push_back({b, i});
}
sort(rbegin(Quer), rend(Quer));
for (auto [i, j] : Quer){
if (j > N)
Add(j - N);
else
get2(idx[j] + 1, cnt[j]);
}
for (int i=1;i<=n;i++){
if (idx[i] != 0 and A[i] < B[i])
swap(A[i], B[i]);
if (cnt[i] % 2 == 0)
Ans += A[i];
else
Ans += B[i];
}
cout<<Ans<<'\n';
}
