#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
vector<pair<int, int>> v;
vector<int> queries, normalizare;
vector<vector<int>> queries_at;
const int NMAX = 600005;
struct ST {
int tree[4 * NMAX + 5];
void update(int poz, int val, int l = 0, int r = NMAX, int node = 1) {
if (l == r) {
tree[node] = val;
return;
}
int mid = (l + r) / 2;
if (poz <= mid) update(poz, val, l, mid, node * 2);
else update(poz, val, mid + 1, r, node * 2 + 1);
tree[node] = max(tree[node * 2], tree[node * 2 + 1]);
}
int query(int left, int right, int l = 0, int r = NMAX, int node = 1) {
if (left > r or l > right or left > right) return 0;
if (l >= left and r <= right) return tree[node];
int mid = (l + r) / 2;
return max(query(left, right, l, mid, 2 * node), query(left, right, mid + 1, r, 2 * node + 1));
}
};
struct ST2 {
int tree[4 * NMAX + 5];
void update(int poz, int val, int l = 0, int r = NMAX, int node = 1) {
if (l == r) {
tree[node] += val;
return;
}
int mid = (l + r) / 2;
if (poz <= mid) update(poz, val, l, mid, node * 2);
else update(poz, val, mid + 1, r, node * 2 + 1);
tree[node] = tree[node * 2] + tree[node * 2 + 1];
}
int query(int left, int right, int l = 0, int r = NMAX, int node = 1) {
if (left > r or l > right or left > right) return 0;
if (l >= left and r <= right) return tree[node];
int mid = (l + r) / 2;
return query(left, right, l, mid, 2 * node) + query(left, right, mid + 1, r, 2 * node + 1);
}
};
ST tree_rmq;
ST2 tree_sum;
int main() {
cin.tie(0)->sync_with_stdio(0);
int n, k;
cin >> n >> k;
v.resize(n + 1);
queries.resize(k + 1);
queries_at.resize(k + 1);
for (int i = 1; i <= n; i++) {
cin >> v[i].first >> v[i].second;
normalizare.push_back(v[i].first);
normalizare.push_back(v[i].second);
}
for (int i = 1; i <= k; i++) {
cin >> queries[i];
normalizare.push_back(queries[i]);
}
sort(normalizare.begin(), normalizare.end());
normalizare.erase(unique(normalizare.begin(), normalizare.end()), normalizare.end());
int M = normalizare.size() - 1;
for (int i = 1; i <= k; i++) {
int poz = lower_bound(normalizare.begin(), normalizare.end(), queries[i]) - normalizare.begin();
tree_rmq.update(poz, i, 0, M);
}
for (int i = 1; i <= n; i++) {
int L_val = min(v[i].first, v[i].second);
int R_val = max(v[i].first, v[i].second);
int left = lower_bound(normalizare.begin(), normalizare.end(), L_val) - normalizare.begin();
int right = lower_bound(normalizare.begin(), normalizare.end(), R_val) - normalizare.begin() - 1;
int last_t = 0;
if (left <= right) last_t = tree_rmq.query(left, right, 0, M);
queries_at[last_t].push_back(i);
}
ll total_cnt = 0;
for (int i = k; i >= 0; i--) {
for (auto it : queries_at[i]) {
int mx = max(v[it].first, v[it].second);
int mn = min(v[it].first, v[it].second);
int poz = lower_bound(normalizare.begin(), normalizare.end(), mx) - normalizare.begin();
int flips = tree_sum.query(poz, M, 0, M);
int current_face;
if (i == 0) current_face = v[it].first;
else current_face = mx;
if (flips % 2 == 1) {
if (current_face == v[it].first) {
total_cnt += v[it].second;
} else {
total_cnt += v[it].first;
}
} else {
total_cnt += current_face;
}
}
if (i > 0) {
int op_poz = lower_bound(normalizare.begin(), normalizare.end(), queries[i]) - normalizare.begin();
tree_sum.update(op_poz, 1, 0, M);
}
}
cout << total_cnt;
}
