#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define ll long long
#define ull unsigned long long
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pli pair<ll, int>
#define debug(x) cout << #x << " = " << x << '\n'
#define all(a) a.begin(), a.end()
#define SZ(a) (int)(a).size()
const int N = 2e5 + 5;
const int mod = 1e9 + 7;
const ll inf64 = 3e18;
const int inf32 = 2e9 + 5;
int n, k, a[N], b[N], t[N];
vector<int> cprs;
const int LG = 20;
int st[LG][N * 3];
int getMax(int l, int r) {
if(r < l) return 0;
int k = __lg(r - l + 1);
return max(st[k][l], st[k][r - (1 << k) + 1]);
}
struct MergeSortTree {
int n;
vector<vector<int>> node;
MergeSortTree(int n) : n(n), node(n << 2) {}
void Merge(vector<int> &a, vector<int> &b, vector<int> &c) {
int i = 0, j = 0;
while(i < SZ(a) && j < SZ(b)) {
if(a[i] < b[j]) c.push_back(a[i++]);
else c.push_back(b[j++]);
}
while(i < SZ(a)) c.push_back(a[i++]);
while(j < SZ(b)) c.push_back(b[j++]);
}
void build(int id, int l, int r) {
if(l == r) {
node[id].push_back(t[l]);
return;
}
int mid = (l + r) >> 1;
build(id << 1, l, mid);
build(id << 1 | 1, mid + 1, r);
Merge(node[id << 1], node[id << 1 | 1], node[id]);
}
int get(int id, int l, int r, int x, int y, int v) {
if(x <= l && r <= y) {
return SZ(node[id]) - (lower_bound(all(node[id]), v) - node[id].begin());
}
int mid = (l + r) >> 1;
if(mid < x) return get(id << 1 | 1, mid + 1, r, x, y, v);
if(mid + 1 > y) return get(id << 1, l, mid, x, y, v);
return get(id << 1, l, mid, x, y, v) + get(id << 1 | 1, mid + 1, r, x, y, v);
}
int get(int l, int r, int x) { return (l <= r ? get(1, 1, n, l, r, x) : 0); }
};
void solve() {
cin >> n >> k;
for(int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
cprs.push_back(a[i]);
cprs.push_back(b[i]);
}
for(int i = 1; i <= k; i++) {
cin >> t[i];
cprs.push_back(t[i]);
}
sort(all(cprs)); cprs.erase(unique(all(cprs)), cprs.end());
auto take = [&](int val) -> int {
return lower_bound(all(cprs), val) - cprs.begin() + 1;
};
for(int i = 1; i <= k; i++)
st[0][take(t[i])] = i;
for(int k = 1; k < LG; k++) {
for(int i = 1; i + (1 << k) - 1 <= SZ(cprs); i++)
st[k][i] = max(st[k - 1][i], st[k - 1][i + (1 << (k - 1))]);
}
MergeSortTree seg(k);
seg.build(1, 1, k);
ll ans = 0;
for(int i = 1; i <= n; i++) {
int mn = min(a[i], b[i]), mx = max(a[i], b[i]);
int p = getMax(take(mn), take(mx) - 1);
if(p > 0) a[i] = mx, b[i] = mn;
int cnt = seg.get(p + 1, k, max(a[i], b[i]));
ans += (cnt & 1 ? b[i] : a[i]);
}
cout << ans << '\n';
}
int main() {
auto start = chrono::steady_clock::now();
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
if(fopen("input.txt", "r")) {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
int test = 1;
// cin >> test;
while(test--) solve();
chrono::duration<double> elapsed {chrono::steady_clock::now() - start};
cerr << "\n>> Runtime: " << elapsed.count() << "s\n";
}
