#include <bits/stdc++.h>
using ll = long long;
#include <ext/pb_ds/assoc_container.hpp>
// #include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef tree<pair<ll, ll>, null_type, less<pair<ll, ll>>, rb_tree_tag, tree_order_statistics_node_update> iset;
#define f first
#define s second
ll a[200001], b[200001];
ll oa[200001], ob[200001];
pair<ll, ll> t[200001], ot[200001];
ll luu[200001];
ll res[200001];
vector<pair<ll, ll>> tam[200002];
struct segtree{
ll n;
vector<ll> tr;
segtree(ll m){
n = m;
tr.resize(4*n);
}
void build(ll node, ll start, ll end){
if(start==end){
tr[node] = luu[end];
}else{
ll mid = (start+end)/2;
build(2*node, start, mid);
build(2*node+1, mid+1, end);
tr[node] = max(tr[2*node], tr[2*node+1]);
}
}
ll query(ll node, ll start, ll end, ll l, ll r){
if(start > r or end < l){
return 0;
}
if(l<=start and end <= r){
return tr[node];
}
ll mid = (start+end)/2;
return max(query(2*node, start, mid, l, r), query(2*node+1, mid+1, end, l, r));
}
};
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
ll n, k;
cin >> n >> k;
map<ll,ll> mp;
for (ll i = 1;i<=n;++i){
cin >> a[i] >> b[i];
oa[i] = a[i], ob[i] = b[i];
mp[a[i]] = -1;
}
for (ll i = 1;i<=n;++i){
mp[b[i]] = -1;
}
for (ll i = 1;i<=k;++i){
cin >> t[i].f;
ot[i].f = t[i].f;
t[i].s = i;
mp[t[i].f] = -1;
}
ll moc = 1;
for (auto &i:mp){
i.second = moc++;
}
for (ll i= 1;i<=n;++i){
a[i] = mp[a[i]];
b[i] = mp[b[i]];
}
for (ll i = 1;i<=k;++i){
t[i].f = mp[t[i].f];
}
sort(t+1, t+k+1);
for (ll i = 1;i<=k;++i){
luu[i] = t[i].s;
}
segtree st(k);
st.build(1, 1, k);
// cout << st.query(1, 1, k, 1, 1);return 0;
for (ll i = 1;i<=n;++i){
res[i] = oa[i];
ll dau = lower_bound(t+1, t+k+1, make_pair(min(a[i], b[i]), (ll)-1)) - t;
ll cuoi = lower_bound(t+1, t+k+1, make_pair(max(a[i], b[i]), (ll)-1)) - t;
// cout << dau << ' ' << cuoi << '\n';
cuoi--;
ll tmp = st.query(1, 1, k, dau, cuoi);
if(tmp!=0){
if(oa[i]<ob[i]){
res[i] = ob[i];
tam[tmp+1].push_back({ob[i], i});
}else{
tam[tmp+1].push_back({oa[i], i});
}
}else{
tam[1].push_back({max(oa[i], ob[i]), i});
}
}
iset s;
for (ll i = k;i>=1;--i){
pair<ll, ll> l = make_pair(ot[i].f, i);
s.insert(l);
for (auto [v, id]:tam[i]){
// cout << v << ' ' << id << ' ' << i << '\n';
ll cnt = s.size()-s.order_of_key(make_pair(v, -1));
// cout << cnt << '\n';
cnt %= 2;
if(cnt==1){
if(res[id]==oa[id])res[id] = ob[id];
else res[id] = oa[id];
}
}
}
/*for (ll i = 1;i<=k;++i){
cout << t[i].f <<
}
ll sol = 0;
for (ll i = 1;i<=n;++i){
cout << a[i] << ' ';
}
cout << '\n';
for (ll i = 1;i<=n;++i){
cout << b[i] << ' ';
}
cout << '\n';*/
long long sol = 0;
for (ll i = 1;i<=n;++i){
sol += res[i];
// cout << res[i] << ' ';
}
cout << sol;
}
