#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
const int N = 200005;
int bit[N], oper[N], n, q, st[N * 4];
pair <int, int> card[N], event[N];
vector <int> vals;
void update_st(int i, int l, int r, int p, int v) {
if (l > p || r < p) return;
st[i] = max(st[i], v);
if (l == r) return;
int m = (l + r) / 2;
update_st(i * 2, l, m, p, v);
update_st(i * 2 + 1, m + 1, r, p, v);
}
int query_st(int i, int l, int r, int lo, int hi) {
if (l > hi || r < lo) return 0;
if (l >= lo && r <= hi) return st[i];
int m = (l + r) / 2;
return max(query_st(i * 2, l, m, lo, hi),
query_st(i * 2 + 1, m + 1, r, lo, hi));
}
int get_id(int x) {
return lower_bound(vals.begin(),
vals.end(), x) - vals.begin() + 1;
}
void update_bit(int i) {
for (; i > 0; i -= i & -i) bit[i]++;
}
int query_bit(int i) {
int res = 0;
for (; i < N; i += i & -i) res += bit[i];
return res;
}
int main() {
/*#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#else
#endif*/
cin.tie(0)->sync_with_stdio(0);
cin >> n >> q; long long res = 0;
for (int i = 1; i <= n; i++)
cin >> card[i].fi >> card[i].se;
for (int i = 1; i <= q; i++) {
cin >> oper[i];
vals.push_back(oper[i]);
}
sort(vals.begin(), vals.end());
for (int i = 1; i <= q; i++) {
oper[i] = get_id(oper[i]);
update_st(1, 1, q, oper[i], i);
}
for (int i = 1, l, r; i <= n; i++) {
tie(l, r) = minmax(card[i].fi, card[i].se);
l = get_id(l); r = get_id(r) - 1;
event[i] = {query_st(1, 1, q, l, r), i};
}
sort(event + 1, event + n + 1);
for (int i = 1, j = 1; i <= n; i++) {
while (j <= event[i].fi) update_bit(oper[j++]);
int last = query_bit(get_id(max(
card[event[i].se].se, card[event[i].se].se)));
int flip = q - get_id((max(card[event[i].se].se,
card[event[i].se].se))) + 1 - last;
if (event[i].fi)
flip ^= card[event[i].se].fi < card[event[i].se].se;
if (flip & 1) res += card[event[i].se].se;
else res += card[event[i].se].fi;
}
cout << res << '\n';
}
