//0 1 1 0 1
//0 1 0 0 1
//1 0 0 1 1
//0 1 1 0 1
//uoy kcuf;
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops")
// #pragma GCC target("avx2")
using namespace std;
#define F first
#define S second
#define pb push_back
#define sze size()
#define all(x) x.begin() , x.end()
#define wall__ cout << "--------------------------------------\n";
#define node int mid = (tl + tr) >> 1, cl = v << 1, cr = v << 1 | 1
#define file_io freopen("input.cpp", "r", stdin); freopen("output.cpp", "w", stdout);
typedef long long ll;
typedef long double dl;
typedef pair < int , int > pii;
typedef pair < int , ll > pil;
typedef pair < ll , int > pli;
typedef pair < ll , ll > pll;
typedef pair < int , pii > piii;
typedef pair < ll, pll > plll;
const ll N = 2e5 + 10;
const ll mod = 1e9 + 7;
const ll inf = 2e16;
const ll rinf = -2e16;
const ll INF = 1e9 + 10;
const ll rINF = -1e9 - 10;
const ll lg = 32;
int n, k, a[N], b[N], c[N];
pii par[N];
vector < pii > kid[N];
vector < pii > ord;
int mx[N << 2];
void build (int v, int tl, int tr) {
if (tl == tr) {
mx[v] = ord[tl].S;
return;
} node;
build(cl, tl, mid);
build(cr, mid + 1, tr);
mx[v] = max(mx[cl], mx[cr]);
}
int find_mx (int l, int r, int v, int tl, int tr) {
if (l > r) return 0;
if (l == tl && r == tr) return mx[v];
node;
return max(find_mx(l, min(r, mid), cl, tl, mid), find_mx(max(l, mid + 1), r, cr, mid + 1, tr));
}
int sit[N], la[N << 2];
void shift (int v, int tl, int tr) {
if (la[v] == 0) return;
if (tl != tr) {
la[v << 1] ^= 1;
la[v << 1 | 1] ^= 1;
} else sit[tl] ^= 1;
la[v] = 0;
}
void upd (int l, int r, int v, int tl, int tr) {
shift(v, tl, tr);
if (l > r) return;
if (l == tl && r == tr) {
la[v] ^= 1;
shift(v, tl, tr);
return;
} node;
upd (l, min(r, mid), cl, tl, mid);
upd (max(l, mid + 1), r ,cr, mid + 1, tr);
}
int pos;
int ask (int v, int tl, int tr) {
shift(v, tl, tr);
if (tl == tr) return sit[tl];
node;
if (pos <= mid) return ask(cl, tl, mid);
else return ask(cr, mid + 1, tr);
}
void solve () {
cin >> n >> k;
vector < piii > g; g.pb({-1, {-1, -1}});
for (int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
g.pb({max(a[i] , b[i]), {a[i], b[i]}});
}
sort(all(g));
// for (auto e : g) cout << e.F << "," << e.S.F <<"," << e.S.S << " | ";
// cout << '\n'; wall__
for (int i = 1; i <= n; i++) {
a[i] = g[i].S.F; b[i] = g[i].S.S;
}
// for (int i = 1; i <= n; i++) cout << a[i] << " , " << b[i] << " | ";
// cout << '\n'; wall__
for (int i = 1; i <= k; i++) {
cin >> c[i];
ord.pb({c[i], i});
}
ord.pb({-1, -1});
sort(all(ord));
// for (int i = 1; i <= k; i++) cout << ord[i].F << "," << ord[i].S << " | ";
// cout << '\n'; wall__
build(1, 1, k);
// cout << "start of find kids : \n";
for (int i = 1; i <= n; i++) {
// cout << i << " : \n";
if (a[i] == b[i]) {
// cout << "do nothing\n"; wall__
continue;
}
int x = a[i], y = b[i]; if (x > y) swap(x, y);
// cout << a[i] << " , " << b[i] << " -- > " << x << " , " << y << '\n';
int t = 0;
if (a[i] < b[i]) t = 1;
// cout << "t = " << t << '\n';
pii X = {x, 0}, Y = {y, 0}; int l = -1, r = k + 1;
if (ord[k].F >= x) l = lower_bound(all(ord), X) - ord.begin();
if (ord[k].F >= y) r = lower_bound(all(ord), Y) - ord.begin();
--r;
// cout << l << " , " << r << '\n';
if (l == -1 || r == 0 || l > r) {
// cout << "do nothing\n"; wall__
continue;
}
int p = find_mx(l, r, 1, 1, k);
// cout << "p = " << p << '\n';
par[i] = {p, t};
kid[p].pb({i, t});
// wall__
}
// cout << "end of find kids\n";
// wall__
// cout << "kids : \n";
// for (int i = 1; i <= k; i++) {
// cout << i << " : ";
// for (auto e : kid[i]) cout << e.F << "," << e.S << " | ";
// cout << '\n';
// }
// wall__
// cout << "start of FUCK!\n";
// wall__
for (int i = 1; i <= k; i++) {
// cout << i << " , " << c[i] << " : \n";
piii CC = {c[i] + 1, {0, 0}};
auto it = lower_bound(all(g), CC);
int id;
if (it == g.end()) id = n;
else {
id = it - g.begin();
--id;
}
// cout << "id = " << id << '\n';
if (id > 0) upd(1, id, 1, 1, n);
for (auto hah : kid[i]) {
int v = hah.F, t= hah.S;
// cout << v << "-" << t << " ; ";
pos = v;
int p = ask(1, 1, n);
// cout << p << '\n';
if (t != p) upd(v, v, 1, 1, n);
}
// wall__
}
// cout << "End of Fuck :(\n";
// wall__
ll ans = 0;
for (int i = 1; i <= n; i++) {
pos = i;
int p = ask(1, 1, n);
// cout << p;
if (p == 1) ans += (1ll * b[i]);
else ans += (1ll * a[i]);
}
// cout << '\n';
// wall__
cout << ans << '\n';
}
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int t = 1;
// cin >> t;
while (t--) {solve();}
return 0;
}
/*
*/
