#include <bits/stdc++.h>
using namespace std;
#define int long long
#define ll long long
#define F first
#define S second
#define pb push_back
#define pii pair<int,int>
const int N = 2e5 + 5;
struct SegTree {
vector<int> st;
int n;
SegTree(int n) : n(n) {
st.resize(4 * n + 5);
}
void update(int id, int l, int r, int i, int x) {
if (i < l || i > r) return;
if (l == r) {
st[id] = x;
return;
}
int mid = (l + r) >> 1;
update(id * 2, l, mid, i, x);
update(id * 2 + 1, mid + 1, r, i, x);
st[id] = max(st[id * 2], st[id * 2 + 1]);
}
int get(int id, int l, int r, int u, int v) {
if (u > v) {
return 0;
}
if (u > r || v < l) return 0;
if (u <= l && r <= v) {
return st[id];
}
int mid = (l + r) >> 1;
return max(get(id * 2, l, mid, u, v), get(id * 2 + 1, mid + 1, r, u, v));
}
};
struct BIT {
int n;
vector<int> bit;
BIT(int n) : n(n) {
bit.resize(n + 3);
}
void update(int id, int val) {
for (int i = id; i <= n; i += (i & -i)) bit[i] += val;
}
int get(int id) {
int res = 0;
for (int i = id; i; i -= (i & -i)) res += bit[i];
return res;
}
};
int n, q;
pii a[N];
pii b[N];
vector<int> cmp;
int t[N];
int last[N];
int cnt[N];
vector<int> event[N];
signed main(){
ios_base::sync_with_stdio(false) ;
cin.tie(0) ; cout.tie(0) ;
if (fopen("INP.INP" ,"r")) {
freopen("INP.INP" ,"r" , stdin) ;
freopen("OUT.OUT" , "w" , stdout) ;
}
cin >> n >> q;
for (int i = 1; i <= n; i++) {
cin >> a[i].F >> a[i].S;
cmp.pb(a[i].F);
cmp.pb(a[i].S);
}
for (int i = 1; i <= q; i++) {
cin >> t[i];
cmp.pb(t[i]);
}
sort(cmp.begin(), cmp.end());
cmp.erase(unique(cmp.begin(), cmp.end()), cmp.end());
for (int i = 1; i <= n; i++) {
b[i].F = upper_bound(cmp.begin(), cmp.end(), a[i].F) - cmp.begin();
b[i].S = upper_bound(cmp.begin(), cmp.end(), a[i].S) - cmp.begin();
if (b[i].F > b[i].S) swap(b[i].F, b[i].S);
}
for (int i = 1; i <= q; i++) {
t[i] = upper_bound(cmp.begin(), cmp.end(), t[i]) - cmp.begin();
}
int sz = cmp.size();
SegTree st(sz);
for (int i = 1; i <= q; i++) {
st.update(1, 1, sz, t[i], i);
}
for (int i = 1; i <= n; i++) {
last[i] = st.get(1, 1, sz, b[i].F, b[i].S - 1);
event[last[i]].pb(i);
}
BIT bit(sz);
for (int i = q; i >= 0; i--) {
// cout << i << ' ' << t[i] << endl;
for (auto j : event[i]) {
// cout << j << ' ';
cnt[j] = bit.get(sz) - bit.get(b[j].S - 1);
} //cout << '\n';
if (i) bit.update(t[i], 1);
}
int res = 0;
for (int i = 1; i <= n; i++) {
if (last[i]) {
int cur = max(a[i].F, a[i].S);
if (cnt[i] & 1) cur = min(a[i].F, a[i].S);
res += cur;
}
else {
int cur = a[i].F;
if (cnt[i] & 1) cur = a[i].S;
res += cur;
}
}
cout << res;
}
