#include <bits/stdc++.h>
using namespace std;
#define TASK "flip"
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
// Segment Tree (iterative)
template<class S, S (*op)(S, S), S (*e)()> struct segtree {
private:
int _n, _size, _log;
vector<S> d;
void updateS(int k) { d[k] = op(d[k << 1], d[k << 1 | 1]); }
constexpr bool ineq(int x, int y, int z) const { return x <= y && y < z; }
public:
segtree() : segtree(0) {}
explicit segtree(int __n) : segtree(vector<S>(__n, e())) {}
explicit segtree(const vector<S> &v) : _n((int)v.size()) {
_log = 31 - __builtin_clz(_n) + ((_n & -_n) != _n), _size = 1 << _log;
d = vector<S>(_size << 1, e());
for (int i = 0; i < _n; ++i) d[_size + i] = v[i];
for (int i = _size - 1; i > 0; --i) updateS(i);
}
S query(int l, int r) { // [l, r)
assert(ineq(0, l, r + 1) && ineq(l, r, _n + 1));
S sml = e(), smr = e();
for (l += _size, r += _size; l < r; l >>= 1, r >>= 1) {
if (l & 1) sml = op(sml, d[l++]);
if (r & 1) smr = op(d[--r], smr);
}
return op(sml, smr);
}
};
int op(int x, int y) { return max(x, y); }
int e() { return 0; }
// End of Segment Tree (iterative)
// Merge Sort Tree
template<class T> struct merge_sort_tree {
int _l, _r, _m;
vector<T> v;
merge_sort_tree *lt, *rt;
merge_sort_tree(int l, int r, const vector<T> &e) : _l(l), _r(r), _m((l + r) >> 1) {
v.resize(r - l + 1), v[0] = e[l];
if (l == r) lt = rt = nullptr;
else {
lt = new merge_sort_tree(_l, _m, e);
rt = new merge_sort_tree(_m + 1, _r, e);
vector<T> v1 = lt->v, v2 = rt->v;
v.resize(v1.size() + v2.size());
merge(all(v1), all(v2), v.begin());
}
}
int count(int l, int r, T a, T b) {
if (a > b) return 0;
if (l > _r || r < _l) return 0;
if (_l >= l && _r <= r) return upper_bound(all(v), b) - lower_bound(all(v), a);
return lt->count(l, r, a, b) + rt->count(l, r, a, b);
}
};
// End of Merge Sort Tree
const int N = 2e5 + 7, N2 = 6e5 + 2, LG = 20;
int n, k, a[N], b[N], t[N], t_idx[N2], max_t_idx[LG][N2];
constexpr int lg2(const int x) { return 31 - __builtin_clz(x); }
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
if (fopen(TASK ".inp", "r")) {
freopen(TASK ".inp", "r", stdin);
freopen(TASK ".out", "w", stdout);
}
cin >> n >> k;
for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
for (int i = 1; i <= k; i++) cin >> t[i];
basic_string<int> cmpr; cmpr.reserve(2 * n + k + 1), cmpr += 0;
for (int i = 1; i <= n; i++) cmpr += a[i], cmpr += b[i];
for (int i = 1; i <= k; i++) cmpr += t[i];
sort(all(cmpr)), cmpr.erase(unique(all(cmpr)), cmpr.end());
auto search = [&](const int v) -> int { return lower_bound(all(cmpr), v) - cmpr.begin(); };
for (int i = 1; i <= n; i++) a[i] = search(a[i]), b[i] = search(b[i]);
for (int i = 1; i <= k; i++) t[i] = search(t[i]), t_idx[t[i]] = i;
// Sparse table
// for (int i = 1; i <= sz(cmpr); i++) max_t_idx[0][i] = t_idx[i];
// for (int j = 1; j < LG; j++)
// for (int i = 1; i + (1 << j) - 1 <= sz(cmpr); i++)
// max_t_idx[j][i] = max(max_t_idx[j - 1][i], max_t_idx[j - 1][i + (1 << (j - 1))]);
// auto query_max_t_idx = [&](int l, int r) -> int {
// int len = lg2(r - l + 1);
// return max(max_t_idx[len][l], max_t_idx[len][r - (1 << len) + 1]);
// };
// End of Sparse table
// Segment Tree (iterative)
segtree<int, op, e> stree(vector<int>(t_idx, t_idx + sz(cmpr) + 1));
auto query_max_t_idx = [&](int l, int r) -> int { return stree.query(l, r + 1); };
// End of Segment Tree (iterative)
// Merge Sort Tree
merge_sort_tree<int> mst(0, k + 1, vector<int>(t, t + k + 1));
// Number of i that (l <= i <= r) and (x <= a[i] <= y)
auto cnt_on_range = [&](int l, int r, int x, int y) -> int {
return mst.count(l, r, x, y);
};
// End of Merge Sort Tree
basic_string<int> ans; ans.reserve(n);
for (int i = 1; i <= n; i++) {
if (a[i] == b[i]) { ans += cmpr[a[i]]; continue; }
bool swapped = (a[i] > b[i] ? (swap(a[i], b[i]), true) : false);
int last_pos = query_max_t_idx(a[i], b[i] - 1);
int cnt_flipped = cnt_on_range(last_pos + 1, k, b[i], sz(cmpr));
if (last_pos != 0 || swapped) swap(a[i], b[i]);
ans += cmpr[~cnt_flipped & 1 ? a[i] : b[i]];
}
// for (int i : ans) cout << i << ' ';
cout << accumulate(ans.begin(), ans.end(), 0LL) << '\n';
}
