/*
Ben Watson
Handle codeforces : quangminh98
Current Theme: Transformers !!!!
*/
#include <bits/stdc++.h>
using namespace std;
#define ll long long
const string name = "test";
void solve();
signed main()
{
if (fopen((name + ".inp").c_str(), "r"))
{
freopen((name + ".inp").c_str(), "r", stdin);
freopen((name + ".out").c_str(), "w", stdout);
}
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
solve();
return 0;
}
// main program
const int maxn = 2e5 + 1;
struct SegmentTree
{
vector<int> st;
int n;
SegmentTree(int n) : n(n) { st.resize(4 * n + 1, 0); }
void update(int head, int l, int r, int pos, int val)
{
if (pos < l || r < pos) return;
if (l == r)
{
st[head] = val;
return;
}
int mid = l + r >> 1;
if (pos <= mid)
update(head << 1, l, mid, pos, val);
else
update(head << 1 | 1, mid + 1, r, pos, val);
st[head] = max(st[head << 1], st[head << 1 | 1]);
}
void update(int pos, int val) { update(1, 1, n, pos, val); }
int query(int head, int l, int r, int u, int v)
{
if (l > v || r < u) return 0;
if (u <= l && r <= v) return st[head];
int mid = l + r >> 1;
return max(query(head << 1, l, mid, u, v), query(head << 1 | 1, mid + 1, r, u, v));
}
int query(int u, int v) { return query(1, 1, n, u, v); }
};
struct FenwickTree
{
vector<int> bits;
int n;
FenwickTree(int n) : n(n) { bits.resize(n + 1, 0); }
void update(int pos, int val)
{
for (; pos <= n; pos += (pos & (-pos)))
bits[pos] += val;
}
int query(int pos)
{
int res = 0;
for (; pos > 0; pos -= (pos & (-pos)))
res += bits[pos];
return res;
}
int query(int l, int r) { return query(r) - query(l - 1); }
};
int n, k;
int a[maxn], b[maxn], T[maxn];
vector<pair<int, int>> cards, ops;
// compression
int cur;
int id[maxn];
vector<int> v;
void solve()
{
cin >> n >> k;
for (int i = 1; i <= n; i++)
{
cin >> a[i] >> b[i];
cards.push_back({max(a[i], b[i]), i});
}
for (int i = 1; i <= k; i++)
{
cin >> T[i];
ops.push_back({T[i], i});
}
sort(cards.begin(), cards.end(), greater<pair<int, int>>());
sort(ops.begin(), ops.end());
// compression
cur = 0;
v.push_back(0);
for (pair<int, int> it : ops)
{
int idx = it.second, val = it.first;
v.push_back(val);
id[idx] = ++cur;
}
reverse(ops.begin(), ops.end());
SegmentTree st(k);
FenwickTree bit(k);
for (int i = 1; i <= k; i++)
st.update(id[i], i);
ll res = 0;
int pos = 0;
for (pair<int, int> it : cards)
{
int mx = it.first, i = it.second;
while (pos < k && ops[pos].first >= mx)
{
int idx = ops[pos].second;
pos++;
st.update(id[idx], 0);
bit.update(idx, 1);
}
int mn = min(a[i], b[i]);
int Q = lower_bound(v.begin() + 1, v.end(), mn) - v.begin();
if (Q == k + 1)
{
int num = bit.query(1, k);
res += ((num % 2 == 0) ? a[i] : b[i]);
} else
{
int index = st.query(Q, k);
int num = (index == k ? 0 : bit.query(index + 1, k));
if (index == 0)
res += (num % 2 == 0 ? a[i] : b[i]);
else
res += (num % 2 == 0 ? (mx == a[i] ? a[i] : b[i]) : (mx == a[i] ? b[i] : a[i]));
}
}
cout << res << '\n';
}
