#include <bits/stdc++.h>
using namespace std;
#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
const int N = 2e5 + 10;
int a[N], b[N];
struct SegmentTree {
vector<int> T;
SegmentTree(int n) {
T.resize(4 * n + 1);
}
void up(int s, int l, int r, int x, int v) {
if (l == r) {
T[s] = v;
return;
}
int mid = (l + r) >> 1;
if (x <= mid) up(s << 1, l, mid, x, v);
else up(s << 1 | 1, mid + 1, r, x, v);
T[s] = max(T[s << 1], T[s << 1 | 1]);
}
int get(int s, int l, int r, int u, int v) {
if (l > v || r < u || u > v) return 0;
if (l >= u && r <= v) return T[s];
int mid = (l + r) >> 1;
return max(get(s << 1, l, mid, u, v), get(s << 1 | 1, mid + 1, r, u, v));
}
};
struct BinaryIndexedTree {
vector<int> bit;
int size;
BinaryIndexedTree(int n) : size(n){
bit.resize(n + 1);
}
void up(int x) {
for (; x; x -= x & -x) ++bit[x];
}
int get(int x) {
int res = 0;
for (; x <= size; x += x & -x) res += bit[x];
return res;
}
};
signed main() {
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
#ifdef LOCAL_MACHINE
if (fopen("task.inp", "r")) {
freopen("task.inp", "r", stdin);
freopen("task.out", "w", stdout);
}
#endif
int n, k; cin >> n >> k;
for (int i = 1; i <= n; ++i) cin >> a[i] >> b[i];
vector<pair<int, int>> q;
for (int i = 1; i <= k; ++i) {
int x; cin >> x;
q.emplace_back(x, i);
}
vector<int> comp;
for (int i = 1; i <= n; ++i) {
comp.push_back(a[i]);
comp.push_back(b[i]);
}
for (int i = 1; i <= k; ++i) comp.push_back(q[i - 1].first);
sort(all(comp));
comp.resize(unique(all(comp)) - comp.begin());
int m = comp.size();
// find last card a <= t < b
SegmentTree it(m);
for (auto &[x, id] : q) {
int p = upper_bound(all(comp), x) - comp.begin();
it.up(1, 1, m, p, id);
}
vector<tuple<int, int, int>> qr;
for (int i = 1; i <= n; ++i) {
int l = upper_bound(all(comp), a[i]) - comp.begin();
int r = upper_bound(all(comp), b[i]) - comp.begin();
if (l > r) swap(l, r);
qr.emplace_back(it.get(1, 1, m, l, r - 1), max(a[i], b[i]), i);
}
// count number of cards after last >= b
sort(all(qr));
reverse(all(q));
BinaryIndexedTree bit(m);
for (auto &[x, id] : q) {
int p = upper_bound(all(comp), x) - comp.begin();
bit.up(p);
while (qr.size() && get<0>(qr.back()) == id) {
auto [_, val, i] = qr.back(); qr.pop_back();
int pos = upper_bound(all(comp), val) - comp.begin();
int cnt = bit.get(pos);
if (cnt & 1) {
if (a[i] > b[i]) swap(a[i], b[i]);
}
else {
if (a[i] < b[i]) swap(a[i], b[i]);
}
}
}
while (qr.size()) {
auto [_, val, i] = qr.back(); qr.pop_back();
int pos = upper_bound(all(comp), val) - comp.begin();
int cnt = bit.get(pos);
if (cnt & 1) swap(a[i], b[i]);
}
ll res = 0;
for (int i = 1; i <= n; ++i) res += a[i];
cout << res << "\n";
}
