#include<bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define vi vector<int>
#define pi pair<int,int>
#define sz(v) (int)(v).size()
#define all(v) (v).begin(), (v).end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
template<class T> using upq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int lwrbound(const vector<T>& a, const T& b, const int s = 0){return int(lower_bound(s + all(a), b) - a.begin());}
template<class T> int uprbound(const vector<T>& a, const T& b, const int s = 0){return int(upper_bound(s + all(a), b) - a.begin());}
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define ROF(i, a, b) for(int i = (a); i >= (b); i--)
#define sumof(x) accumulate(all(x), 0ll)
#define dbg(x) "[" << #x " = " << (x) << "]"
#define el "\n"
using ll = long long;
using ld = long double;
template<class T> bool ckmx(T& a, const T b){return (a < b ? a = b, true : false);}
template<class T> bool ckmn(T& a, const T b){return (a > b ? a = b, true : false);}
const int N = 2e5 + 5;
const int MOD = 1e9 + 7;
const ll INF = numeric_limits<ll>::max() / 8;
/*
a[i] <= b[i]
Type 1: a[i] <= T[j] < b[i] -> swap only a[i] to b[i]
Type 2: b[i] <= T[j] -> swap both a[i], b[i]
a[i]..... Type 1.... b[i]
b[i]..... Type 1.... b[i]
-> we will find the last type 1 and calculate the answer
*/
struct SegTree{
vector<int> st; int trsz;
SegTree(int n = 0): st((n << 2) | 1), trsz(n) {}
void update(int id, int l, int r, int x, int p){
if(l == r){
st[id] = max(st[id], p);
}
else{
int m = l+r>>1;
if(x <= m)
update(id << 1, l, m, x, p);
else update(id << 1|1, m+1, r, x, p);
st[id] = max(st[id << 1], st[id << 1|1]);
}
}
int get(int id, int l, int r, int u, int v){
if(l > v || r < u) return 0;
if(l >= u && r <= v) return st[id];
int m = l+r>>1;
return max(get(id << 1, l, m, u, v), get(id << 1|1, m+1, r, u, v));
}
void update(int x, int p){
update(1, 0, trsz, x, p);
}
int query(int l, int r){
if(l > r) return 0;
return get(1, 0, trsz, l, r);
}
};
struct IT{
vector<vi> st; int trsz;
IT(int n, vector<int>& a): st((n << 2) | 1), trsz(n){
build(1, 0, n, a);
}
void merge_st(int id, int l, int r){
int i = 0, j = 0;
while(i < sz(st[l]) && j < sz(st[r])){
if(st[l][i] < st[r][j]){
st[id].eb(st[l][i]);
i++;
}
else{
st[id].eb(st[r][j]);
j++;
}
}
while(i < sz(st[l])) st[id].eb(st[l][i++]);
while(j < sz(st[r])) st[id].eb(st[r][j++]);
}
void build(int id, int l, int r, vector<int>& a){
if(l == r){
st[id].eb(a[l]);
}
else{
int m = l+r>>1;
build(id << 1, l, m, a);
build(id << 1|1, m+1, r, a);
merge_st(id, id << 1, id << 1|1);
}
}
int query(int l, int r, int k){
return query(1, 0, trsz, l, r, k);
}
int query(int id, int l, int r, int u, int v, int k){
if(l >= u && r <= v) return (sz(st[id]) - lwrbound(st[id], k));
int m = l+r>>1;
return (u <= m ? query(id << 1, l, m, u, v, k) : 0) +
(v > m ? query(id << 1|1, m+1, r, u, v, k) : 0);
}
};
void Main()
{
int n,k; cin >> n >> k;
vi a(n + 1), b(n + 1);
FOR(i, 1, n) cin >> a[i] >> b[i];
vi Q(k + 1); FOR(i, 1, k) cin >> Q[i];
vi comp(1, -1);
FOR(i, 1, k) comp.eb(Q[i]);
sort(all(comp)), compact(comp);
SegTree st(sz(comp)); IT tr(k, Q);
FOR(i, 1, k){
Q[i] = lwrbound(comp, Q[i]);
st.update(Q[i], i);
}
auto brute = [&](int i) -> int{
int cur = a[i], t = 0;
for(int j = 1; j <= k; j++){
if(comp[Q[j]] >= cur){
if(!t) cur = b[i];
else cur = a[i];
t ^= 1;
}
}
return cur;
};
ll ans = 0;
FOR(i, 1, n){
if(a[i] > b[i]) swap(a[i], b[i]);
int x = lwrbound(comp, a[i]);
int y = lwrbound(comp, b[i]);
int lst = st.query(x, y - 1);
int change = tr.query(lst + 1, n, b[i]);
ans += (((change & 1) ^ (!lst)) ? a[i] : b[i]);
}
cout << ans << el;
}
int32_t main()
{
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
#define name "InvMOD"
if(fopen(name".INP", "r")){
freopen(name".INP", "r", stdin);
freopen(name".OUT", "w", stdout);
}
int t = 1; while(t--) Main();
return 0;
}
