#include <bits/stdc++.h>
#define ar array
//#define int long long
using namespace std;
using ll = long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
const int mod = 1e9 + 7;
const ll inf = 1e18;
const int maxn = 1e5 + 5;
struct persistent_sgt {
struct node {
int sum = 0;
node *l, *r;
node(int _s=0) : sum(_s), l(nullptr), r(nullptr) {}
node(node *l, node *r) : l(l), r(r) {
if(l) sum += l->sum;
if(r) sum += r->sum;
}
};
int n;
vector<node*> R;
persistent_sgt(int _n) : n(_n) {
R.push_back(build(1, n));
}
node* build(int l, int r) {
if(l == r) return new node();
int m = (l + r) / 2;
return new node(build(l, m), build(m+1, r));
}
node *update(node *u, int tl, int tr, int p) {
if(tl == tr) return new node(1);
int tm = (tl + tr) / 2;
if(p <= tm) return new node(update(u->l, tl, tm, p), u->r);
return new node(u->l, update(u->r, tm+1, tr, p));
}
int find(node *u, node *v, int tl, int tr) {
if(u->sum - v->sum == 0) return 0;
if(tl == tr) return tl;
int tm = (tl + tr) / 2;
if(u->r->sum - v->r->sum > 0) return find(u->r, v->r, tm+1, tr);
return find(u->l, v->l, tl, tm);
}
int query(node *u, int tl, int tr, int l, int r) {
if(tl > r || l > tr) return 0;
if(l <= tl && tr <= r) return u->sum;
int tm = (tl + tr) / 2;
return query(u->l, tl, tm, l, r) + query(u->r, tm+1, tr, l, r);
}
int find(int x, int y) {
return find(R[x], R[y], 1, n);
}
void update(int p) {
R.push_back(update(R.back(), 1, n, p));
}
int query(int u, int l, int r) {
return query(R[u], 1, n, l, r);
}
};
bool cmp(int x, int y) {
return x >= y;
}
signed main() {
ios_base::sync_with_stdio(false);
cout.tie(0); cin.tie(0);
int n, q; cin >> n >> q;
vector<int> a(n+1), b(n+1);
set<int> st;
st.insert(0); st.insert(2e9);
for(int i=1; i<=n; i++) {
cin >> a[i] >> b[i];
st.insert(a[i]);
st.insert(b[i]);
}
vector<int> vec(st.begin(), st.end());
vector<pii> qus;
for(int i=1; i<=q; i++) {
int x; cin >> x;
qus.push_back({ x, i });
st.insert(x);
}
vector<int> comp(st.begin(), st.end());
sort(qus.rbegin(), qus.rend());
sort(vec.rbegin(), vec.rend());
int m = comp.size(), k = vec.size();
persistent_sgt psgt(q);
vector<int> sz(k);
int j = 0;
for(int i=0; i<k; i++) {
while(j < qus.size() && qus[j].first >= vec[i]) {
psgt.update(qus[j].second);
j++;
}
sz[i] = psgt.R.size();
}
vector<int> pos(n+1);
for(int i=1; i<=n; i++) {
if(a[i] == b[i]) continue;
int L = min(a[i], b[i]), R = max(a[i], b[i]);
L = lower_bound(vec.begin(), vec.end(), L, cmp) - vec.begin();
R = lower_bound(vec.begin(), vec.end(), R, cmp) - vec.begin();
pos[i] = psgt.find(sz[L-1]-1, sz[R-1]-1);
}
for(int i=1; i<=n; i++) {
if(a[i] == b[i]) continue;
if(pos[i] && a[i] < b[i]) swap(a[i], b[i]);
if(pos[i] == q) continue;
// cout << i << ": " << a[i] << " " << b[i] << '\n';
int p = lower_bound(vec.begin(), vec.end(), max(a[i], b[i]), cmp) - vec.begin();
int cnt = psgt.query(sz[p-1]-1, pos[i]+1, q);
// cout << i << ": " << cnt << '\n';
if(cnt & 1) swap(a[i], b[i]);
}
ll ans = 0;
for(int i=1; i<=n; i++) ans += a[i];
cout << ans << '\n';
}
