#include<bits/stdc++.h>
using namespace std;
#define int long long
//#define endl '\n'
#define F first
#define S second
#define SZ(a) int32_t(a.size())
namespace RMQ {
const int N = 6e5 + 7, LG = 20;
int rmq[LG][N];
void add(int i, int k) {
rmq[0][i] = k;
return;
}
void pre(int n) {
for (int i = 0; i < LG - 1; ++i)
for (int j = 0; j + (2 << i) <= n; ++j)
rmq[i + 1][j] = max(rmq[i][j], rmq[i][j + (1 << i)]);
return;
}
int get(int l, int r) {
int L = __lg(r - l);
return max(rmq[L][l], rmq[L][r - (1 << L)]);
}
}
namespace FEN {
const int N = 6e5 + 7;
bitset<N> fen;
bool f;
void add(int i) {
f = !f;
i++;
for (; i < N; i += (i & -i))
fen[i] = !fen[i];
return;
}
bool get(int i) {
i++;
bool ret = 0;
for (; i; i -= (i & -i)) {
ret ^= fen[i];
}
return ret;
}
bool gets(int i) {
return f ^ get(i - 1);
}
}
const int N = 6e5 + 7;
struct rmp {
int mn, mx;
}mp[N];
int n, q, a[N], b[N], t[N], ans;
pair<int, int> f[N];
vector<int> com, sv1[N];
vector<pair<int, int>> sv2;
void ip() {
cin >> n >> q;
for (int i = 0; i < n; ++i) {
cin >> a[i] >> b[i];
mp[i].mn = min(a[i], b[i]);
mp[i].mx = max(a[i], b[i]);
com.push_back(a[i]);
com.push_back(b[i]);
}
for (int i = 0; i < q; ++i) {
cin >> t[i];
com.push_back(t[i]);
}
return;
}
void compres() {
sort(com.begin(), com.end());
com.resize(unique(com.begin(), com.end()) - com.begin());
for (int i = 0; i < n; i++)
a[i] = lower_bound(com.begin(), com.end(), a[i]) - com.begin(),
b[i] = lower_bound(com.begin(), com.end(), b[i]) - com.begin();
for (int i = 0; i < q; i++)
t[i] = lower_bound(com.begin(), com.end(), t[i]) - com.begin();
return;
}
void pre() {
for (int i = 0; i < q; ++i)
f[i] = {t[i], i};
sort(f, f + q);
for (int i = 0; i < q; ++i)
RMQ::add(i, f[i].S);
RMQ::pre(q);
return;
}
void solve() {
for (int i = 0; i < n; ++i) {
int mn = min(a[i], b[i]), mx = max(a[i], b[i]), l;
pair<int, int> a1 = {mn, -1}, b1 = {mx, -1};
int bsn = lower_bound(f, f + q, a1) - f;
int bsx = upper_bound(f, f + q, b1) - f;
(bsn >= bsx) ? l = - 1 : l = RMQ::get(bsn, bsx);
// cout << mn << " " << mx << " " << bsn << " " << bsx << " " << l << endl;
bool pb = (a[i] <= b[i]);
(l == -1) ? sv2.push_back({pb , i}) : sv1[l].push_back(i);
}
for (int i = q - 1; ~i; --i) {
// cout << "gg" << i << " " << sv1[i].size() << endl;
for (auto j : sv1[i]) {
int l = 0;
int mx = max(a[j], b[j]);
l ^= FEN::gets(mx);
ans += (l ? mp[j].mn : mp[j].mx);
}
FEN::add(t[i]);
}
for (auto i: sv2) {
int l = i.F;
int mx = max(a[i.S], b[i.S]);
l ^= FEN::gets(mx);
ans += (l ? mp[i.S].mn : mp[i.S].mx);
}
return;
}
void op() {
cout << ans;
return;
}
void run() {
ip();
compres();
pre();
solve();
op();
return;
}
signed main() {
ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
run();
return 0;
}
