// #pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
using namespace std;
#define el "\n"
#define pii pair<int, int>
#define pll pair<ll, ll>
#define fi first
#define se second
#define mp make_pair
#define sqr(x) ((x) * (x))
#define FOR(i, l, r) for (int i = l; i <= (r); i++)
#define FOD(i, l, r) for (int i = l; i >= (r); i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sz(x) ((int)(x).size())
#define fast_io ios_base::sync_with_stdio(false); cin.tie(nullptr);
using db = long double;
using ll = long long;
using ull = unsigned long long;
using vi = vector<int>;
using vll = vector<ll>;
using vpii = vector<pii>;
using vpll = vector<pll>;
using vvi = vector<vi>;
using vvll = vector<vll>;
using vbool = vector<bool>;
using vvbool = vector<vbool>;
template<class T> inline bool chmax(T &a, T const &b) { return (a < b ? (a = b, true) : false); }
template<class T> inline bool chmin(T &a, T const &b) { return (a > b ? (a = b, true) : false); }
// #define DEBUG
#ifdef DEBUG
#include "D:\cpp\debug.h"
#else
#define debug(...)
#define debug_arr(...)
#endif
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count());
constexpr int N = 2E5 + 5;
constexpr int INF = 1E9 + 7;
constexpr ll INFLL = 4E18;
constexpr int MOD = 1E9 + 7; // 998244353
constexpr double EPS = 1E-10;
template<class T> struct SegmentTree {
int n;
vector<T> tree;
SegmentTree(int n): n(n), tree(4 * n + 5) {}
void update(int i, int l, int r, int k, T val) {
if (l > r || l > k || k > r) return;
if (l == r) {
tree[i] = val;
return;
}
int m = (l + r) / 2;
update(i * 2, l, m, k, val);
update(i * 2 + 1, m + 1, r, k, val);
tree[i] = max(tree[i * 2], tree[i * 2 + 1]);
}
T query(int i, int l, int r, int ql, int qr) {
if (l > r || l > qr || r < ql || ql > qr) return 0;
if (l >= ql && r <= qr) return tree[i];
int m = (l + r) / 2;
return max(query(i * 2, l, m, ql, qr), query(i * 2 + 1, m + 1, r, ql, qr));
}
void update(int k, T val) { return update(1, 1, n, k, val); }
T query(int ql, int qr) { return query(1, 1, n, ql, qr); }
};
template<class T> struct BIT {
int n;
vector<T> bit;
BIT(int n): n(n), bit(n + 5) {}
void update(int i, T val) {
for (; i <= n; i += i & -i) {
bit[i] += val;
}
}
T query(int i) const {
T res = 0;
for (; i >= 1; i -= i & -i) {
res += bit[i];
}
return res;
}
T query(int l, int r) const {
return query(r) - query(l - 1);
}
};
struct Card {
int a, b, t, state;
Card() = default;
Card(int a, int b, int t): a(a), b(b), t(t), state(0) {}
} card[N];
int threshold[N];
int n, k;
void solve() {
cin >> n >> k;
vi vals;
FOR(i, 1, n) {
int a, b;
cin >> a >> b;
card[i] = {a, b, 0};
vals.push_back(a);
vals.push_back(b);
}
FOR(i, 1, k) {
cin >> threshold[i];
vals.push_back(threshold[i]);
}
sort(all(vals));
vals.erase(unique(all(vals)), vals.end());
auto compress = [&vals](int x) {
return int(lower_bound(all(vals), x) - vals.begin()) + 1;
};
FOR(i, 1, n) {
card[i].a = compress(card[i].a);
card[i].b = compress(card[i].b);
if (card[i].a > card[i].b) {
swap(card[i].a, card[i].b);
card[i].state = 1;
}
}
const int MAX = 2 * n + k + 5;
SegmentTree<int> st(MAX);
FOR(i, 1, k) {
threshold[i] = compress(threshold[i]);
st.update(threshold[i], i);
}
FOR(i, 1, n) {
card[i].t = st.query(card[i].a, card[i].b - 1);
}
sort(card + 1, card + n + 1, [](Card const &a, Card const &b) {
return a.t > b.t;
});
BIT<int> ft(MAX);
int j = k;
FOR(i, 1, n) {
if (card[i].t > 0) card[i].state = 1;
while (j > card[i].t) {
ft.update(threshold[j], +1);
j--;
}
int cnt = ft.query(card[i].b, MAX);
card[i].state ^= cnt & 1;
}
ll res = 0;
FOR(i, 1, n) {
int idx = card[i].state == 0 ? card[i].a : card[i].b;
res += vals[idx - 1];
}
cout << res << el;
}
int main() {
fast_io
#define LOCAL
#ifndef LOCAL
#define PROBLEM ""
freopen(PROBLEM ".INP", "r", stdin);
freopen(PROBLEM ".OUT", "w", stdout);
#endif
int t = 1;
// cin >> t;
while (t--) solve();
}
