#define taskname "test"
#include <bits/stdc++.h>
using namespace std;
#define sz(x) (int)x.size()
#define fi first
#define se second
typedef long long lli;
typedef pair<int, int> pii;
const int maxn = 6e5 + 5;
int n, k;
pii cards[maxn];
int t[maxn];
vector<int> vals;
vector<int> pos_val[maxn];
struct segment_tree
{
int max_pos[maxn * 4], total[maxn * 4];
void add_pos(int x, int l, int r, int p, int k)
{
if(l == r)
{
max_pos[x] = max(max_pos[x], k);
return;
}
int mid = (l + r) / 2;
if(p <= mid) add_pos(x * 2, l, mid, p, k);
else add_pos(x * 2 + 1, mid + 1, r, p, k);
max_pos[x] = max(max_pos[x * 2], max_pos[x * 2 + 1]);
}
int get_max_pos(int x, int l, int r, int L, int R)
{
if(L > r || l > R) return 0;
if(l >= L && r <= R)
return max_pos[x];
int mid = (l + r) / 2;
return max(get_max_pos(x * 2, l, mid, L, R),
get_max_pos(x * 2 + 1, mid + 1, r, L, R));
}
void add(int x, int l, int r, int p)
{
if(l == r)
{
++total[x];
return;
}
int mid = (l + r) / 2;
if(p <= mid) add(x * 2, l, mid, p);
else add(x * 2 + 1, mid + 1, r, p);
total[x] = total[x * 2] + total[x * 2 + 1];
}
int get_total(int x, int l, int r, int L, int R)
{
if(L > r || l > R || L > R) return 0;
if(l >= L && r <= R)
return total[x];
int mid = (l + r) / 2;
return get_total(x * 2, l, mid, L, R) + get_total(x * 2 + 1, mid + 1, r, L, R);
}
} tree;
void read_input()
{
cin >> n >> k;
for(int i = 1; i <= n; ++i)
cin >> cards[i].fi >> cards[i].se;
for(int i = 1; i <= k; ++i)
cin >> t[i];
}
int lwb(const vector<int>&arr, int k)
{
return lower_bound(arr.begin(), arr.end(), k) - arr.begin() + 1;
}
void init()
{
for(int i = 1; i <= n; ++i)
{
vals.push_back(cards[i].fi);
vals.push_back(cards[i].se);
}
for(int i = 1; i <= k; ++i)
vals.push_back(t[i]);
sort(vals.begin(), vals.end());
vals.erase(unique(vals.begin(), vals.end()), vals.end());
for(int i = 1; i <= n; ++i)
{
cards[i].fi = lwb(vals, cards[i].fi);
cards[i].se = lwb(vals, cards[i].se);
}
for(int i = 1; i <= k; ++i)
{
t[i] = lwb(vals, t[i]);
tree.add_pos(1, 1, sz(vals), t[i], i);
pos_val[t[i]].push_back(i);
}
sort(cards + 1, cards + n + 1, [](pii p, pii q)
{
return max(p.fi, p.se) > max(q.fi, q.se);
});
}
void solve()
{
lli ans = 0;
for(int i = 1, j = sz(vals); i <= n; ++i)
{
if(cards[i].fi == cards[i].se)
{
ans += vals[cards[i].fi - 1];
continue;
}
int mx = max(cards[i].fi, cards[i].se);
int mn = min(cards[i].fi, cards[i].se);
while(j >= mx)
{
for(auto&p: pos_val[j])
tree.add(1, 1, k, p);
--j;
}
int p = tree.get_max_pos(1, 1, sz(vals), mn, mx - 1);
int t = tree.get_total(1, 1, k, p + 1, k);
if(p > 0)
ans += (t & 1 ? vals[mn - 1] : vals[mx - 1]);
else ans += (t & 1 ? vals[cards[i].se - 1] : vals[cards[i].fi - 1]);
}
cout << ans << '\n';
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
read_input();
init();
solve();
}
