#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using ll = long long int;
#define all(a) a.begin(), a.end()
const int Mxn = 6e5 + 2;
struct segtree_sum {
vector<int> segs;
segtree_sum() {segs.assign(Mxn<<1, 0);}
void upd(int i, int x) {
i += Mxn; segs[i] += x;
for (i >>= 1; i; i >>= 1) {
segs[i] = segs[i<<1] + segs[i<<1|1];
}
}
int query(int l, int r, int ans = 0) {
for (l += Mxn, r += Mxn + 1; l < r; l >>= 1, r >>= 1) {
if (l&1) ans += segs[l++];
if (r&1) ans += segs[--r];
}
return ans;
}
};
struct segtree_max {
vector<int> segs;
segtree_max() {segs.assign(Mxn<<1, -1);}
void upd(int i, int x) {
i += Mxn; segs[i] = x;
for (i >>= 1; i; i >>= 1) {
segs[i] = max(segs[i<<1], segs[i<<1|1]);
}
}
int query(int l, int r, int ans = -1) {
for (l += Mxn, r += Mxn + 1; l < r; l >>= 1, r >>= 1) {
if (l&1) ans = max(segs[l++], ans);
if (r&1) ans = max(segs[--r], ans);
}
return ans;
}
};
struct query {
int idx, sufix, val;
bool operator<(const query & X) {return sufix > X.sufix;}
};
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
int n, k, cnt = 0; cin >> n >> k;
ll ans = 0;
map<int, int> cc;
map<ll, ll> anti;
vector<pii> A(n);
for (auto &[x, y] : A) cin >> x >> y;
vector<int> T(k);
for (auto &e : T) cin >> e;
for (auto [x, y] : A) cc[x], cc[y];
for (auto e : T) cc[e];
for (auto &[x, y] : cc) y = cnt++;
for (auto &[x, y] : A) x = cc[x], y = cc[y];
for (auto &e : T) e = cc[e];
for (auto [x, y] : cc) anti[y] = x;
segtree_max St_max;
vector<query> Count(n);
for (int i = 0; i < k; i++) {
St_max.upd(T[i], i);
}
for (int i = 0; i < n; i++) {
auto &[idx, sufix, val] = Count[i];
idx = i;
auto [l, r] = A[i];
if (l > r) {
sufix = St_max.query(r, l - 1);
val = l;
} else {
sufix = St_max.query(l, r - 1);
val = r;
}
}
sort(all(Count));
cnt = 0;
segtree_sum St_sum; vector<int> Ans(n);
for (int i = k - 1; i >= 0; i--) {
while (cnt < n && Count[cnt].sufix == i) {
auto &[idx, sufix, val] = Count[cnt++];
Ans[idx] = St_sum.query(val, Mxn - 1);
}
St_sum.upd(T[i], 1);
}
for (int i = 0; i < n; i++) {
auto [l, r] = A[i];
if (l > r) {
swap(l, r);
if (St_max.query(l, r - 1) == -1) {
if (St_sum.query(r, Mxn - 1)&1) ans += anti[l];
else ans += anti[r];
} else {
if (Ans[i]&1) ans += anti[l];
else ans += anti[r];
}
} else {
if (St_max.query(l, r - 1) == -1) {
if (St_sum.query(r, Mxn - 1)&1) ans += anti[r];
else ans += anti[l];
} else {
if (Ans[i]&1) ans += anti[l];
else ans += anti[r];
}
}
}
cout << ans << '\n';
}
