#pragma GCC optimize("O2")
#include <bits/stdc++.h>
#ifdef DEBUG
#include "debug.hpp"
#endif
using namespace std;
#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 DEBUG
#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>;
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;
}
};
/*
class BIT{
int n;
vi a;
void upd(int i, int v){
for(i++; i <= n; i += i & -i)
a[i] += v;
}
public:
inline BIT(int _n){
n = _n;
a.resize(n + 1);
}
inline void rupd(int l, int r){
upd(l, 1), upd(r, -1);
}
int qry(int i) const{
int s = 0;
for(i++; i; i -= i & -i)
s += a[i];
return s;
}
};
*/
class dynamicSegtree2D{
class segtree1D{
int n;
struct node{
int v = 0;
node* l = 0;
node* r = 0;
};
using pnode = node*;
pnode root = 0;
void update(pnode& t, int s, int e, int i, int v){
if(i < s || e < i) return;
if(!t) t = new node();
t->v += v;
debug(s, e, i, v, t->v);
if(s != e)
update(t->l, s, (s + e) >> 1, i, v), update(t->r, (s + e + 2) >> 1, e, i, v);
}
// [s, e]
int query(pnode t, int s, int e, int l, int r){
if(!t || r < s || e < l) return 0;
debug(s, e, l, r, t->v);
if(l <= s && e <= r) return t->v;
else return query(t->l, s, (s + e) >> 1, l, r) + query(t->r, (s + e + 2) >> 1, e, l, r);
}
public:
inline segtree1D(int _n = 0){ n = _n; }
inline void update(int i, int v){ update(root, 0, n - 1, i, v); }
inline int query(int l, int r){ return query(root, 0, n - 1, l, r); }
};
int n, k;
vector<segtree1D> seg;
public:
inline dynamicSegtree2D(int _n, int _k){ n = _n; k = _k; seg = vector<segtree1D>(n << 1, segtree1D(k)); }
void update(int i, int j, int v){
debug(i, j, v);
for(i += n; i; i >>= 1){
debug(i, j);
seg[i].update(j, v);
}
}
// [s1, e1], [s2, e2] and (1 -> index, 2 -> value)
int query(int s1, int e1, int s2, int e2){
int ans = 0;
for(s1 += n, e1 += n + 1; s1 < e1; s1 >>= 1, e1 >>= 1){
if(s1 & 1) {
debug(s1, s2, e2, seg[s1].query(s2, e2));
ans += seg[s1++].query(s2, e2);
}
if(e1 & 1) {
debug(e1, seg[e1 - 1].query(s2, e2));
ans += seg[--e1].query(s2, e2);
}
}
return ans;
}
};
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());
dynamicSegtree2D seg2(K, compress.size());
debug(T);
rep(i, K) {
seg.update(T[i], i);
seg2.update(i, T[i], 1);
}
debug(seg2.query(0, K - 1, 1, compress.size() - 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]);
int k = seg2.query(t + 1, K - 1, r, compress.size() - 1);
debug(i, l, r, t, k);
if(k & 1) swap(A[i], B[i]);
}
cout << accumulate(all(A), 0LL) << '\n';
#ifdef DEBUG
dbg::dout << "\nExecution time: " << clock() << "ms\n";
#endif
return 0;
}
