#include<bits/stdc++.h>
#define fi first
#define se second
#define endl "\n"
#define ii pair<int, int>
using namespace std;
const int N = 2e5 + 10, M = 6e5;
int a[N], b[N], c[N], T[M * 4 + 10], bit[N], ans[N];
int n, m;
vector<int> rrh, lst[M + 10];
vector<pair<int, int> > query[M + 10];
int id(int x) {
return upper_bound(rrh.begin(), rrh.end(), x) - rrh.begin();
}
void up(int s, int l, int r, int pos, int val) {
if (l == r) {
T[s] = max(T[s], val);
return;
}
int mid = l + r >> 1;
if (pos <= mid) up(s << 1, l, mid, pos, val);
else up(s << 1 | 1, mid + 1, r, pos, val);
T[s] = max(T[s << 1], T[s << 1 | 1]);
}
int get(int s, int l, int r, int from, int to) {
if (l > to || r < from) return 0;
if (from <= l && r <= to) return T[s];
int mid = l + r >> 1;
return max(get(s << 1, l, mid, from, to), get(s << 1 | 1, mid + 1, r, from, to));
}
void upbit(int pos, int val) {
while (pos) {
bit[pos] += val;
pos -= pos & -pos;
}
}
int getbit(int pos) {
int ret = 0;
while (pos <= m) {
ret += bit[pos];
pos += pos & -pos;
}
return ret;
}
int main() {
#define task ""
cin.tie(0) -> sync_with_stdio(0);
if (fopen ("task.inp", "r")) {
freopen ("task.inp", "r", stdin);
freopen ("task.out", "w", stdout);
}
if (fopen (task".inp", "r")) {
freopen (task".inp", "r", stdin);
freopen (task".out", "w", stdout);
}
cin >> n >> m;
for(int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
rrh.push_back(a[i]);
rrh.push_back(b[i]);
}
for(int i = 1; i <= m; i++) {
cin >> c[i];
rrh.push_back(c[i]);
}
sort(rrh.begin(), rrh.end());
rrh.resize(unique(rrh.begin(), rrh.end()) - rrh.begin());
int sz = rrh.size();
for(int i = 1; i <= m; i++) {
lst[id(c[i])].push_back(i);
up(1, 1, sz, id(c[i]), i);
}
for(int i = 1; i <= n; i++) {
int pos = get(1, 1, sz, id(min(a[i], b[i])), id(max(a[i], b[i])) - 1);
if (pos && a[i] < b[i]) ans[i] = 1;
query[id(max(a[i], b[i]))].emplace_back(pos + 1, i);
}
for(int i = sz; i >= 1; i--) {
for(int &j : lst[i]) upbit(j, 1);
for(auto &it : query[i]) {
int pos, idx; tie(pos, idx) = it;
ans[idx] += getbit(pos);
}
}
long long res = 0;
for(int i = 1; i <= n; i++) {
if (ans[i] % 2) res += b[i];
else res += a[i];
}
cout << res;
}
