#pragma GCC optimization ("unroll-loops")
#pragma GCC optimization ("O1, O2, O3, Ofast")
#pragma GCC optimization ("trapv")
#pragma GCC optimization ("sse, sse2, sse3, sse4, sse4.1, sse4.2, avx, avx2")
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define max_heap priority_queue<ll>
#define min_heap priority_queue<pair <ll, ll>, vector<pair <ll, ll>>, greater<pair <ll, ll>>>
//#define min_heap priority_queue<ll, vector<ll>, greater<ll>>
#define sariE cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define filE freopen("in.txt", "r", stdin); freopen("out1.txt", "w", stdout);
#define endl '\n'
#define md(a) (a % mod + mod) % mod
//cout << setprecision(5) << f;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
ll const maxn = 6e5 + 123;
ll const inf = 2e18;
ll const loG = 23;
//ll const mod = 1e9 + 7;
ll const mod = 998244353;
ll const sq = 350;
ll power(ll a, ll b, ll mod){return b ? 1LL * power(1LL * a * a % mod, b / 2, mod) * (b % 2 ? a : 1) % mod : 1;}
ll n, k, arr[maxn][2], brr[maxn], chi[maxn], sz = 2;
vector <ll> seg[2], adad[maxn], comp;
vector <pair <pair <ll, ll>, ll>> qu[maxn];
bool av[maxn];
void setter1(ll i, ll val, ll x, ll lx, ll rx){
if (rx - lx == 1){
seg[0][x] = max(seg[0][x], val);
return;
}
ll mid = (lx + rx) / 2, a = 2 * x + 1, b = a + 1;
if (i < mid)
setter1(i, val, a, lx, mid);
else
setter1(i, val, b, mid, rx);
seg[0][x] = max(seg[0][a], seg[0][b]);
}
ll get1(ll l, ll r, ll x, ll lx, ll rx){
if (l >= rx || lx >= r)
return 0;
//cout << l << ' ' << r << ' ' << x << " " << lx << " " << rx << endl;
if (l <= lx && rx <= r){
//cout << "tah " << lx << " " << seg[0][x] << endl;
return seg[0][x];
}
ll mid = (lx + rx) / 2, a = 2 * x + 1, b = a + 1;
ll ret1 = get1(l, r, a, lx, mid);
ll ret2 = get1(l, r, b, mid, rx);
return max(ret1, ret2);
}
void setter2(ll i, ll val, ll x, ll lx, ll rx){
if (rx - lx == 1){
seg[1][x] += val;
return;
}
ll mid = (lx + rx) / 2, a = 2 * x + 1, b = a + 1;
if (i < mid)
setter2(i, val, a, lx, mid);
else
setter2(i, val, b, mid, rx);
seg[1][x] = seg[1][a] + seg[1][b];
}
ll get2(ll l, ll r, ll x, ll lx, ll rx){
if (l >= rx || lx >= r)
return 0;
//cout << l << ' ' << r << ' ' << x << " " << lx << " " << rx << endl;
if (l <= lx && rx <= r){
//cout << "tah " << lx << " " << seg[0][x] << endl;
return seg[1][x];
}
ll mid = (lx + rx) / 2, a = 2 * x + 1, b = a + 1;
ll ret1 = get2(l, r, a, lx, mid);
ll ret2 = get2(l, r, b, mid, rx);
return ret1 + ret2;
}
void solve(){
cin >> n >> k;
for (int i = 1; i < n + 1; i++){
cin >> arr[i][0] >> arr[i][1];
comp.push_back(arr[i][0]);
comp.push_back(arr[i][1]);
if (arr[i][0] > arr[i][1]){
av[i] = 1;
swap(arr[i][0], arr[i][1]);
}
}
for (int i = 1; i < k + 1; i++){
cin >> brr[i];
comp.push_back(brr[i]);
}
sort(comp.begin(), comp.end());
comp.resize(unique(comp.begin(), comp.end()) - comp.begin());
ll cnt = 0;
while (sz <= comp.size())
sz = sz * 2;
while (sz <= k)
sz = sz * 2;
seg[0].resize(2 * sz);
seg[1].resize(2 * sz);
//cout << "new" << endl;
for (int i = 1; i < n + 1; i++){
ll x = lower_bound(comp.begin(), comp.end(), arr[i][0]) - comp.begin() + 1;
chi[x] = arr[i][0];
arr[i][0] = x;
x = lower_bound(comp.begin(), comp.end(), arr[i][1]) - comp.begin() + 1;
chi[x] = arr[i][1];
arr[i][1] = x;
//cout << arr[i][0] << ' ' << arr[i][1] << endl;
}
for (int i = 1; i < k + 1; i++){
ll x = lower_bound(comp.begin(), comp.end(), brr[i]) - comp.begin() + 1;
chi[x] = brr[i];
brr[i] = x;
adad[brr[i]].push_back(i);
//cout << brr[i] << endl;
setter1(brr[i], i, 0, 0, sz);
}
ll ans = 0;
for (int i = 1; i < n + 1; i++){
if (arr[i][0] == arr[i][1]){
ans += chi[arr[i][0]];
continue;
}
ll mx = get1(arr[i][0], arr[i][1], 0, 0, sz);
if (mx == k){
ans += chi[arr[i][1]];
continue;
}
qu[arr[i][1]].push_back({{mx + 1, k}, i});
//cout << i << ' ' << mx << endl;
}
//cout << "ans was " << ans << endl;
for (int i = maxn - 1; i > 0; i--){
if (adad[i].size() == 0 && qu[i].size() == 0)
continue;
//cout << adad[i].size() << ' ' << qu[i].size() << endl;
//cout << i << " started " << endl;
for (ll x : adad[i]){
//cout << "setting " << x << endl;
setter2(x, 1, 0, 0, sz);
}
for (auto p : qu[i]){
//cout << "qu " << p.first.first << ' ' << p.first.second << ' ' << p.second << endl;
ll t = get2(p.first.first, p.first.second + 1, 0, 0, sz);
//cout << "tot was " << t << endl;
if (p.first.first == 1){
if (t % 2 == 0){
ans += chi[arr[p.second][av[p.second]]];
}
else{
ans += chi[arr[p.second][1 - av[p.second]]];
}
}
else{
if (t % 2){
ans += chi[arr[p.second][0]];
}
else{
ans += chi[arr[p.second][1]];
}
}
//cout << ans << endl;
}
}
cout << ans << endl;
}
int main(){
//sariE;// filE;
ll test = 1;
//cin >> test;
while (test--) solve();
}
