//In the name of Allah :)
#include <bits/stdc++.h>
using namespace std;
string to_string(char c) { return string(1,c); }
string to_string(bool b) { return b ? "true" : "false"; }
string to_string(const char* s) { return (string)s; }
string to_string(string s) { return s; }
string to_string(vector<bool> v) {
string res = "{"; for(int i = 0; i < (int)v.size(); i++) res += char('0'+v[i]);
res += "}"; return res; }
template<size_t SZ> string to_string(bitset<SZ> b) {
string res = ""; for(size_t i = 0; i < SZ; i++) res += char('0'+b[i]);
return res; }
template<class A, class B> string to_string(pair<A,B> p);
template<class T> string to_string(T v) { // containers with begin(), end()
bool fst = 1; string res = "{";
for (const auto& x: v) {
if (!fst) res += ", ";
fst = 0; res += to_string(x);
}
res += "}"; return res;
}
template<class A, class B> string to_string(pair<A,B> p) {
return "("+to_string(p.first)+", "+to_string(p.second)+")"; }
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
cerr << to_string(h); if (sizeof...(t)) cerr << ", ";
DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define wis(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "] : [", DBG(__VA_ARGS__)
#else
#define wis(...) 0
#endif
typedef long long ll;
#define all(x) (x).begin(), (x).end()
const int MAXN = 2e5 + 10;
int n, k, a[MAXN], b[MAXN], t[MAXN];
vector<int> seg[MAXN << 2];
void build(int nd, int cl, int cr) {
if (cr - cl == 1) {
seg[nd] = {t[cl]};
return;
}
int L = nd << 1, R = L | 1, mid = (cr + cl) >> 1;
build(L, cl, mid);
build(R, mid, cr);
seg[nd].resize(seg[L].size() + seg[R].size());
merge(seg[L].begin(), seg[L].end(), seg[R].begin(), seg[R].end(), seg[nd].begin());
}
inline void build() {
build(1, 0, k);
}
int query(int nd, int cl, int cr, int ind, int val) {
if (cl >= ind) {
return seg[nd].end() - lower_bound(all(seg[nd]), val);
}
if (ind >= cr) {
return 0;
}
int L = nd << 1, R = L | 1, mid = (cr + cl) >> 1, ret = 0;
if (ind >= mid) {
ret = query(R, mid, cr, ind, val);
}
else {
ret = query(L, cl, mid, ind, val) + query(R, mid, cr, ind, val);
}
return ret;
}
inline int query(int ind, int val) { // return how many numbers after ind has value greater than or equal val
int ret = query(1, 0, k, ind, val);
return ret;
}
inline int last(int l, int r) { //[l, r]
if (l > r) {
return -1;
}
auto check = [&](int mid) {
return query(mid, l) - query(mid, r + 1) > 0;
};
int bl = -1, br = k;
while (br - bl > 1) {
int mid = (bl + br) >> 1;
if (check(mid)) {
bl = mid;
}
else {
br = mid;
}
}
return bl;
}
int main() {
ios::sync_with_stdio(0);
#ifndef LOCAL
cin.tie(0);
#endif
cin >> n >> k;
for (int i = 0; i < n; i++) {
cin >> a[i] >> b[i];
}
for (int i = 0; i < k; i++) {
cin >> t[i];
}
build();
ll ans = 0;
for (int i = 0; i < n; i++) {
int lst = last(min(a[i], b[i]), max(a[i], b[i]) - 1);
int cnt = query(lst + 1, max(a[i], b[i]));
wis(a[i], b[i], lst, cnt);
if (lst == -1) {
if (cnt % 2 == 0) {
wis(a[i]);
ans += a[i];
}
else {
wis(b[i]);
ans += b[i];
}
}
else {
if (b[i] > a[i]) {
swap(a[i], b[i]);
}
if (cnt % 2 == 0) {
wis(a[i]);
ans += a[i];
}
else {
wis(b[i]);
ans += b[i];
}
}
}
cout << ans << '\n';
}
