#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>
using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
// /*
// //////////**DEFINES - START**//////////
#define ret return
#define fi first
#define se second
#define mp make_pair
#define all(x) x.begin(), x.end()
#define be(x) x.begin()
#define en(x) x.end()
#define sz(x) ll(x.size())
#define for0(i, n) for (ll i = 0; i < (n); ++i)
#define for1(i, n) for (ll i = 1; i < (n); ++i)
#define rfor0(i, n) for (ll i = (n) - 1; i >= 0; --i)
#define rfor1(i, n) for (ll i = (n) - 1; i >= 1; --i)
#define rep(i, a, n) for (ll i = a; i < ll(n); ++i)
#define rrep(i, a, n) for (ll i = a - 1; i >= ll(n); --i)
#define popcount __builtin_popcount
#define popcountll __builtin_popcountll
#define fastIO() ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define con continue
#define pb push_back
#define pob pop_back
#define deb(x) cout << (#x) << " is " << (x) << endl
#define ins insert
#define len(s) (s).length()
#define gi greater<int>()
#define gll greater<ll >()
#define gstr greater<string>()
#define gpll greater<pair<ll , ll >>()
#define rast(x1, y1, x2, y2) sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2))
#define rev reverse
#define ub upper_bound
#define lb lower_bound
#define bs binary_search
#define rs resize
#define last(a) a.back()
#define co count
#define ba(a) a.back()
#define um unordered_map
#define rsun(a) a.resize(unique(a.begin(), a.end())-a.begin())
#define endl '\n'
#ifdef OG_Matveychick1
bool local = true;
#else
bool local = false;
#endif
// \\\\\\\\\\**DEFINES - END**\\\\\\\\\\
// */
// /*
// //////////**TYPEDEFS - START**//////////
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<char> vc;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
typedef vector<string> vs;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<ull> vull;
typedef pair<ll, ll> pll;
typedef vector<ll> vll;
typedef vector<pll> vpll;
typedef pair<double, double> pdd;
typedef double ld;
typedef double D;
typedef vector<ld> vld;
typedef vector<pair<ld, ld>>
vpld;
typedef string str;
typedef set<ll> sll;
typedef set<int> si;
typedef set<str> ss;
typedef set<pii> spii;
typedef multiset<int> msi;
typedef multiset<ll> msll;
typedef multiset<str> mss;
typedef multiset<pii> mspii;
typedef multiset<pll> mspll;
typedef map<str, str> mps;
typedef map<int, int> mpi;
typedef map<ll, ll> mpll;
typedef map<int, vi> mpvi;
typedef map<int, vll> mpvll;
typedef map<char, int> mpci;
typedef multimap<ll, ll> mmpll;
typedef multimap<str, str> mmps;
typedef multimap<int, int> mmpi;
typedef vector<vector<int>> vvi;
typedef vector<vector<ll>> vvll;
typedef vector<vector<long double>> vvld;
typedef vector<vvi> vvvi;
typedef vector<vector<char>> vvc;
typedef vector<vs> vvs;
typedef vector<D> vD;
typedef set<pair<ll, ll>>
spll;
typedef pair<ull, ull> pull;
typedef vector<pull> vpull;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef set<char> sc;
typedef queue<int> qi;
typedef queue<ll> qll;
typedef queue<bool> qb;
typedef vector<sll> vsll;
typedef queue<pair<ll, ll>>
qpll;
typedef vector<vector<pair<int, int>>>
vvpii;
typedef vector<vector<pair<ll, ll>>>
vvpll;
typedef vector<spll> vspll;
typedef multiset<char> msc;
typedef queue<str> qs;
typedef vector<set<int>> vsi;
typedef priority_queue<ll> pqll;
typedef vector<vsll> vvsll;
typedef pair<ld, ld> pld;
typedef vector<vvll> vvvll;
typedef set<ld> sld;
typedef vector<vpld> vvpld;
typedef tree<ll, null_type, less<ll>, rb_tree_tag, tree_order_statistics_node_update>
ordered_set;
typedef tree<ll, null_type, less_equal<ll>, rb_tree_tag, tree_order_statistics_node_update>
ordered_multiset;
// \\\\\\\\\\**TYPEDEFS - END**\\\\\\\\\\
// */
// /*
// //////////**CONSTANTS - START**//////////
const ld pi = acosl(-1);
const ll mod1 = 1e9 + 7;
const ll mod2 = 998244353;
const ll MAXLL = 9223372036854775807;
//const ll MAXINT = 2147483647;
const ld eps = 1e-6;
// \\\\\\\\\\**CONSTANTS - END**\\\\\\\\\\
// */
// /*
// //////////**TEMPLATES - START**//////////
template<typename T>
istream &operator>>(istream &in, vector<T> &a) {
for (T &i: a) in >> i;
return in;
}
template<typename T1, typename T2>
istream &operator>>(istream &in, pair<T1, T2> &a) {
in >> a.fi >> a.se;
return in;
}
template<typename T1, typename T2>
ostream &operator<<(ostream &out, pair<T1, T2> &a) {
out << a.fi << " " << a.se;
return out;
}
template<typename T1, typename T2>
istream &operator>>(istream &in, vector<pair<T1, T2>>
&a) {
for (
pair<T1, T2> &i
: a)
in >> i.fi >> i.
se;
return
in;
}
template<typename T>
ostream &operator<<(ostream &out, const vector<T> &a) {
for (auto i: a) {
out << i << " ";
}
return out;
}
template<typename T1, typename T2>
ostream &operator<<(ostream &out, vector<pair<T1, T2>>
&a) {
for (
pair<T1, T2> i
: a)
out << i.fi << " " << i.se <<
endl;
return
out;
}
template<typename T1>
ostream &operator<<(ostream &out, vector<vector<T1>> &a) {
for (vector<T1> i: a) {
for (T1 j: i) out << j << " ";
out << endl;
}
return out;
}
template<typename T1, typename T2>
inline T1 min(T1 a, T2 b) {
b = (T1) b;
return a > b ? b : a;
}
template<typename T1, typename T2>
inline T1 max(T1 a, T2 b) {
b = (T1) b;
return a > b ? a : b;
}
template<typename T1, typename T2>
inline void amin(T1 &a, T2 b) {
a = min(a, b);
}
template<typename T1, typename T2>
inline void amax(T1 &a, T2 b) {
a = max(a, b);
}
// \\\\\\\\\\**TEMPLATES - END**\\\\\\\\\\
// */
// This bear is a good alternative to duck!!!
/*
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*/
ld getTime() {
return (ld) clock() / (ld) CLOCKS_PER_SEC;
}
mt19937_64 rn(chrono::steady_clock::now().time_since_epoch().count());
//mt19937_64 rn(4);
ll rnd(ll l, ll r) {
ll a = rn() % (r - l + 1) + l;
return a;
}
void solve();
ll T = 1;
signed main(int argc, char **argv) {
// setlocale(LC_ALL, "RUS");
fastIO()
cout.precision(12);
cout << fixed;
if (local && argc == 1) {
freopen("input.txt", "r", stdin);
// freopen("output.txt", "w", stdout);
}
// cin >> T;
while (T--) {
solve();
}
if (local && argc == 1) {
cout << endl << fixed << "time = " << getTime();
}
return 0;
}
const ll N = 1 << 20;
ll a[N], b[N], t[N], n, k, lst[N];
vll t1[2 * N], t2[2 * N];
vll s;
void add1(ll v, ll l, ll r, ll L, ll R, ll i) {
if (l >= R || r <= L) ret;
if (l >= L && r <= R) {
t1[v].pb(i);
ret;
}
ll m = (l + r) / 2;
add1(v * 2, l, m, L, R, i);
add1(v * 2 + 1, m, r, L, R, i);
}
void add1(ll l, ll r, ll i) {
add1(1, 0, N, l, r, i);
}
void go1(ll v, ll l, ll r, ll p, ll i) {
if (l > p || r <= p) ret;
for (auto x: t1[v]) if (lst[x] == -1) lst[x] = i;
t1[v].clear();
if (l + 1 == r) ret;
ll m = (l + r) / 2;
go1(v * 2, l, m, p, i);
go1(v * 2 + 1, m, r, p, i);
}
void go1(ll p, ll i) {
go1(1, 0, N, p, i);
}
void build(ll v, ll l, ll r) {
if (l + 1 == r) {
t2[v] = {t[l]};
ret;
}
ll m = (l + r) / 2;
build(v * 2, l, m);
build(v * 2 + 1, m, r);
t2[v].rs(sz(t2[v * 2]) + sz(t2[v * 2 + 1]));
merge(all(t2[v * 2]), all(t2[v * 2 + 1]), be(t2[v]));
}
void build() {
build(1, 0, k);
}
ll get(ll v, ll l, ll r, ll L, ll R, ll x) {
if (l >= R || r <= L) ret 0;
if (l >= L && r <= R) ret en(t2[v]) - lb(all(t2[v]), x);
ll m = (l + r) / 2;
ret get(v * 2, l, m, L, R, x) + get(v * 2 + 1, m, r, L, R, x);
}
ll get(ll l, ll r, ll x) {
ret get(1, 0, k, l, r, x);
}
void solve() {
cin >> n >> k;
for0(i, n) cin >> a[i] >> b[i], lst[i] = -1, s.pb(a[i]), s.pb(b[i]);
for0(i, k) cin >> t[i], s.pb(t[i]);
sort(all(s));
rsun(s);
for0(i, n) a[i] = lb(all(s), a[i]) - be(s), b[i] = lb(all(s), b[i]) - be(s);
for0(i, k) t[i] = lb(all(s), t[i]) - be(s);
for0(i, n) add1(min(a[i], b[i]), max(a[i], b[i]), i);
rfor0(i, k) go1(t[i], i);
ll ans = 0;
build();
for0(i, n) {
if (lst[i] != -1 && a[i] < b[i]) swap(a[i], b[i]);
ll c = get(lst[i] + 1, k, max(a[i], b[i]));
ans += s[(c & 1 ? b[i] : a[i])];
}
cout << ans;
}
