#pragma GCC optimize("O2")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#ifdef DEBUG
#include "debug.hpp"
#endif
using namespace std;
using namespace __gnu_pbds;
#define all(c) (c).begin(), (c).end()
#define traverse(c, it) for(auto it = (c).begin(); it != (c).end(); it++)
#define rep(i, N) for(int i = 0; i < (N); i++)
#define rep1(i, N) for(int i = 1; i <= (N); i++)
#define rep2(i, s, e) for(int i = (s); i <= (e); i++)
#define rep3(i, s, e, d) for(int i = (s); (d) >= 0 ? i <= (e) : i >= (e); i += (d))
#define pb push_back
#ifdef XDEBUG
#define debug(x...) {dbg::depth++; string dbg_vals = dbg::to_string(x); dbg::depth--; dbg::fprint(__func__, __LINE__, #x, dbg_vals);}
#define light_debug(x) {dbg::light = 1; dbg::dout << __func__ << ":" << __LINE__ << " " << #x << " = " << x << endl; dbg::light = 0;}
#else
#define debug(x...)
#define light_debug(x)
#endif
template<typename T>
T& ckmin(T& a, T b){ return a = a > b ? b : a; }
template<typename T>
T& ckmax(T& a, T b){ return a = a < b ? b : a; }
using ll = long long;
using pii = pair<int, int>;
using vi = vector<int>;
using ordered_multiset = tree<pii, null_type, less<pii>, rb_tree_tag, tree_order_statistics_node_update>;
class Compress{
vi vals;
public:
inline int rank(int x) const{
return lower_bound(all(vals), x) - vals.begin();
}
Compress(vi& v){
vals = v;
sort(all(vals));
vals.erase(unique(all(vals)), vals.end());
for(auto& x : v) x = rank(x);
}
inline int size() const{
return vals.size();
}
};
class segtree{
int n;
vi seg;
inline void pull(int i){
seg[i] = max(seg[i << 1], seg[i << 1 | 1]);
}
public:
inline segtree(int _n){
n = _n;
seg.resize(n << 1);
fill(all(seg), -1);
}
void update(int i, int v){
for(ckmax(seg[i += n], v), i >>= 1; i; i >>= 1)
pull(i);
}
// [s, e)
int query(int s, int e) const{
int m = -1;
for(s += n, e += n; s < e; s >>= 1, e >>= 1){
if(s & 1) ckmax(m, seg[s++]);
if(e & 1) ckmax(m, seg[--e]);
}
return m;
}
};
signed main(){
ios_base::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
#ifdef DEBUG
freopen("debug", "w", stderr);
#endif
int N, K;
cin >> N >> K;
vi A(N), B(N), T(K);
rep(i, N) cin >> A[i] >> B[i];
rep(i, K) cin >> T[i];
Compress compress(T);
segtree seg(compress.size());
debug(T);
rep(i, K) seg.update(T[i], i);
struct query{ int r, i; };
vector<vector<query>> qs(K + 1);
rep(i, N){
int l = compress.rank(A[i]);
int r = compress.rank(B[i]);
if(l > r) swap(l, r);
int t = seg.query(l, r);
if(t != -1 && A[i] < B[i]) swap(A[i], B[i]);
debug(i, t, l, r)
qs[t + 1].pb({r, i});
}
ordered_multiset S;
rep3(i, K - 1, 0, -1){
S.insert({T[i], i});
for(auto& q : qs[i]){
if((K - i - S.order_of_key({q.r, -1})) & 1)
swap(A[q.i], B[q.i]);
}
}
cout << accumulate(all(A), 0LL) << '\n';
#ifdef DEBUG
dbg::dout << "\nExecution time: " << clock() << "ms\n";
#endif
return 0;
}
