#include <bits/stdc++.h>
#define dbgv(v) {for(auto x:v)cout<<x<<' ';cout<<'\n';}
#define entire(v) v.begin(),v.end()
typedef long long ll;
using namespace std;
void OJize(){
cin.tie(NULL); ios_base::sync_with_stdio(false);
#ifdef jh
freopen("input.txt", "r", stdin);
#endif
}
// 0-indexed
template <typename T>
struct Segtree{
T id = -2147483647;
T combine(T a, T b){
return max(a, b);
}
int n; vector<T> arr;
Segtree(int sz): n{1} {
while(n < sz) n<<=1;
arr.resize(n*2);
}
void update(int i, T val){
for(arr[i+=n] = val; i > 1; i/= 2) arr[i/2] = combine(arr[i], arr[i^1]);
}
T query(int l, int r){
T resl = id, resr = id;
for(l+= n, r+= n+1; l < r; l/= 2, r/= 2){
if(l&1) resl = combine(resl, arr[l++]);
if(r&1) resr = combine(resr, arr[--r]);
}
return combine(resl, resr);
}
};
// 0-indexed
template <typename T>
struct Fenwick{
int n; vector<T> arr;
Fenwick(int n): n{n}, arr{vector<T>(n)} {}
void construct(vector<T>& A){
for(int i=0; i<n; i++) arr[i] = A[i];
for(int i=0; i<n; i++) if((i|(i+1)) < n) arr[i|(i+1)]+= arr[i];
}
void update(int i, T val){
while(i < n) arr[i]+= val, i |= i+1;
}
T getsum(int i){
T res = 0;
while(i >= 0) res+= arr[i], i = (i&(i+1))-1;
return res;
}
T intersum(int i, int j){
return i? (getsum(j) - getsum(i-1)) : getsum(j);
}
};
/*
* Treat each card individually, wlog a<b. (if a=b, trivial; if a>b, flip once.)
* each operation x is either
* 1. x < a: never flip
* 2. a <= x < b: set to "flipped"
* 3. b <= x: always flip
* so we need to find the last occurrence of a<=x<b, then count the number of b<=x after that point.
* last occurrence: max segtree
* count b<=x after some point: offline sum segtree
*/
int main(){OJize();
// Input and compression
int n, k; cin>>n>>k;
vector<tuple<int, int, int>> card(n); // max(a,b), a, b, index 0-i
vector<pair<int, int>> query(k); // x, index 1-i
map<int, int> com;
for(int i=0; i<n; i++){
int a, b; cin>>a>>b;
card[i] = make_tuple(-max(a, b), a, b);
com[a] = com[b] = 0;
}
for(int i=0; i<k; i++) cin>>query[i].first, query[i].second = i+1, com[query[i].first] = 0;
int i = 0;
for(auto it = com.begin(); it != com.end(); it++) it->second = i++;
sort(entire(card));
sort(entire(query));
// Segtrees
Segtree<int> maxst(com.size()); // last index of query x, compressed, 1-i
for(auto &xi: query) maxst.update(com[xi.first], xi.second);
Fenwick<int> F(k+1); // current occurrence of large query at i, 1-i
// Computation
ll ans = 0;
int CI = k-1;
for(auto& tup: card){
// Get compressed a and b
int mab, ra, rb; tie(mab,ra,rb) = tup;
if(ra == rb){ans+= ra; continue;}
int a = com[ra], b = com[rb];
if(a > b) swap(a, b);
// Update large-number queries
while(CI >= 0 && query[CI].first >= -mab){
F.update(query[CI].second, 1);
CI--;
}
// Count flips
int last = maxst.query(a, b-1), flip = F.intersum(last, F.n-1) % 2, val;
if(last == 0) val = flip? rb : ra;
else val = ((ra>rb)^flip)? ra : rb;
ans+= val;
//cout <<ra<<' '<<rb<<" -> "<<a<<' '<<b<<" -> "<<last<<" last; "<<flip<<" flips; "<<val<<'\n';
}
cout << ans;
}
