#include "bits/stdc++.h"
#define int long long
using namespace std;
const long long INF = 1ll << 60;
const int N = 6e5 + 5;
const int L = 20;
int suf[N];
int a[N], b[N], n, k, t[N], MN[N], MX[N], T[L][N];
array<int, 2> srt_t[N];
vector<int> d;
vector<array<int, 2>> V[N], non;
bitset<N> bit;
bool kol = 0;
void add(int r) {
kol ^= 1;
r++;
for (; r < N; r += r & -r) bit[r] = bit[r] ^ 1;
}
bool get(int r) {
r++;
bool re = 0;
for (; r; r -= r & -r) re ^= bit[r];
return re;
}
bool get_suf(int r) {
return kol ^ get(r - 1);
}
int rmq(int l, int r) {
int t = __lg(r - l);
return max(T[t][l], T[t][r - (1 << t)]);
}
signed main() {
ios::sync_with_stdio(0), cin.tie(0);
cin >> n >> k;
for (int i = 0; i < n; i++) {
cin >> a[i] >> b[i];
d.push_back(a[i]);
d.push_back(b[i]);
MN[i] = min(a[i], b[i]);
MX[i] = max(a[i], b[i]);
}
for (int i = 0; i < k; i++) {
cin >> t[i];
d.push_back(t[i]);
}
sort(d.begin(), d.end());
d.resize(unique(d.begin(), d.end()) - d.begin());
for (int i = 0; i < n; i++)
a[i] = lower_bound(d.begin(), d.end(), a[i]) - d.begin(),
b[i] = lower_bound(d.begin(), d.end(), b[i]) - d.begin();
for (int i = 0; i < k; i++)
t[i] = lower_bound(d.begin(), d.end(), t[i]) - d.begin();
for (int i = 0; i < k; i++)
srt_t[i] = {t[i], i};
sort(srt_t, srt_t + k);
for (int i = 0; i < k; i++)
T[0][i] = srt_t[i][1];
for (int l = 0; l < L - 1; l++)
for (int i = 0; i + (2 << l) <= k; i++)
T[l + 1][i] = max(T[l][i], T[l][i + (1 << l)]);
for (int i = 0; i < n; i++) {
int mn = min(a[i], b[i]), l, mx = max(a[i], b[i]);
int ind1 = lower_bound(srt_t, srt_t + k, array<int, 2>{mn, -1}) - srt_t;
int ind2 = upper_bound(srt_t, srt_t + k, array<int, 2>{mx, -1}) - srt_t;
if (ind1 >= ind2) l = -1;
else l = rmq(ind1, ind2);
//cout << "LATEST " << l + 1 << '\n';
int q;
if (l == -1) {
q = (a[i] <= b[i]);
non.push_back({q, i});
}
else {
q = 0;
V[l].push_back({q, i});
}
}
int S = 0;
for (int i = k - 1; i >= 0; i--) {
for (auto p: V[i]) {
int q = p[0];
int mx = max(a[p[1]], b[p[1]]);
q ^= get_suf(mx);
S += (q ? MN[p[1]] : MX[p[1]]);
}
add(t[i]);
}
for (auto p: non) {
int q = p[0];
int mx = max(a[p[1]], b[p[1]]);
q ^= get_suf(mx);
S += (q ? MN[p[1]] : MX[p[1]]);
//cout << (q ? MN[p[1]] : MX[p[1]]) << ' ';
}
cout << S << '\n';
return 0;
}
//به زآن که فروشند چه خواهند خرید
