#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef tree<int, null_type, greater<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef long long ll;
struct segtree {
vector<int> a, b;
int n = 0;
int o = 0;
int merge(int x, int y) {
return max(x, y);
}
void start(int x) {
n = x;
for (int i = 0; i <= n; i++) a.push_back(o);
for (int i = 0; i <= 4 * n; i++) b.push_back(o);
n = 0;
}
void insertVal(int x) {
n++;
a[n] = x;
}
void build(int d, int l, int r) {
if (l == r) b[d] = a[l];
else {
int mid = (l + r) / 2;
build(d * 2, l, mid);
build(d * 2 + 1, mid + 1, r);
b[d] = merge(b[d * 2], b[d * 2 + 1]);
}
}
void update(int d, int l, int r, int v, int x) {
if (l == r) {
b[d] = merge(b[d], x);
} else {
int mid = (l + r) / 2;
if (v <= mid) update(d * 2, l, mid, v, x);
else update(d * 2 + 1, mid + 1, r, v, x);
b[d] = merge(b[d * 2], b[d * 2 + 1]);
}
}
int query(int d, int l, int r, int u, int v) {
if (u > v) return o;
else if (l == u && r == v) return b[d];
else {
int mid = (l + r) / 2;
return merge(query(d * 2, l, mid, u, min(mid, v)), query(d * 2 + 1, mid + 1, r, max(mid + 1, u), v));
}
}
};
struct segtree2 {
vector<int> a, b;
int n = 0;
int o = 0;
int merge(int x, int y) {
return x + y;
}
void start(int x) {
n = x;
for (int i = 0; i <= n; i++) a.push_back(o);
for (int i = 0; i <= 4 * n; i++) b.push_back(o);
n = 0;
}
void insertVal(int x) {
n++;
a[n] = x;
}
void build(int d, int l, int r) {
if (l == r) b[d] = a[l];
else {
int mid = (l + r) / 2;
build(d * 2, l, mid);
build(d * 2 + 1, mid + 1, r);
b[d] = merge(b[d * 2], b[d * 2 + 1]);
}
}
void update(int d, int l, int r, int v, int x) {
if (l == r) {
b[d] = merge(b[d], x);
} else {
int mid = (l + r) / 2;
if (v <= mid) update(d * 2, l, mid, v, x);
else update(d * 2 + 1, mid + 1, r, v, x);
b[d] = merge(b[d * 2], b[d * 2 + 1]);
}
}
int query(int d, int l, int r, int u, int v) {
if (u > v) return o;
else if (l == u && r == v) return b[d];
else {
int mid = (l + r) / 2;
return merge(query(d * 2, l, mid, u, min(mid, v)), query(d * 2 + 1, mid + 1, r, max(mid + 1, u), v));
}
}
};
struct foot {
int x, idx;
};
const int MAX = 2e5 + 2;
pair<int, int> a[MAX];
int b[MAX], d[MAX], n, k;
foot c[MAX];
bool cmp(foot x, foot y) {
return x.x > y.x;
}
void solve() {
cin >> n >> k;
map<int, int> mp, mp1;
for (int i = 1; i <= n; i++) {
cin >> a[i].first >> a[i].second;
if (a[i].first > a[i].second) {
swap(a[i].first, a[i].second);
d[i] = 1;
}
mp[a[i].first]++;
mp[a[i].second]++;
}
for (int i = 1; i <= k; i++) {
cin >> b[i];
mp[b[i]]++;
}
int cnt = 0;
for (auto i : mp) {
mp[i.first] = ++cnt;
mp1[cnt] = i.first;
}
for (int i = 1; i <= n; i++) {
a[i].first = mp[a[i].first];
a[i].second = mp[a[i].second];
}
for (int i = 1; i <= k; i++) b[i] = mp[b[i]];
int m = mp.size();
segtree st;
st.start(m);
for (int i = 1; i <= m; i++) st.insertVal(0);
st.build(1, 1, m);
for (int i = 1; i <= k; i++) st.update(1, 1, m, b[i], i);
for (int i = 1; i <= n; i++) {
int temp = st.query(1, 1, m, a[i].first, a[i].second - 1);
c[i] = {temp, i};
//cout << temp << " ";
}
//cout << "\n";
sort(c + 1, c + n + 1, cmp);
segtree2 st2;
st2.start(m);
for (int i = 1; i <= m; i++) st2.insertVal(0);
st2.build(1, 1, m);
int j = k;
ll res = 0;
for (int i = 1; i <= n; i++) {
while (j > c[i].x) {
st2.update(1, 1, m, b[j], 1);
j--;
}
int temp = st2.query(1, 1, m, a[c[i].idx].second, m);
int temp1;
if (c[i].x == 0) {
if ((d[c[i].idx] + temp) % 2 == 0) temp1 = a[c[i].idx].first;
else temp1 = a[c[i].idx].second;
} else {
if (temp % 2 == 0) temp1 = a[c[i].idx].second;
else temp1 = a[c[i].idx].first;
}
res += mp1[temp1];
//cout << c[i].idx << " " << mp1[temp1] << "\n";
}
cout << res;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
solve();
}
