#include <bits/stdc++.h>
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define FOD(i, a, b) for(int i = (a); i >= (b); i--)
#define ALL(x) (x).begin(), (x).end()
#define file(name) if(fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
#define fi first
#define se second
#define el cout << '\n'
#define maxn int(2e5 + 5)
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
struct SegmentTree {
int n;
vector<int> t;
SegmentTree(int __n = 0) {
n = __n;
t.assign(n << 2 | 3, 0);
}
void update(int pos, int val, int id, int l, int r) {
if(pos < l || r < pos) return;
if(l == r) {
t[id] = val;
return;
}
int mid = (l + r) >> 1;
update(pos, val, id << 1, l, mid);
update(pos, val, id << 1 | 1, mid + 1, r);
t[id] = max(t[id << 1], t[id << 1 | 1]);
}
int get(int u, int v, int id, int l, int r) {
if(v < l || r < u || v < u) return 0;
if(u <= l && r <= v) return t[id];
int mid = (l + r) >> 1;
return max(get(u, v, id << 1, l, mid), get(u, v, id << 1 | 1, mid + 1, r));
}
void update(int pos, int val) {
update(pos, val, 1, 1, n);
}
int get(int u, int v) {
return get(u, v, 1, 1, n);
}
};
struct FenwickTree {
int n;
vector<int> t;
FenwickTree(int __n = 0) {
n = __n;
t.assign(n + 3, 0);
}
void update(int x, int v) {
for(; x <= n; x += x & -x) t[x] += v;
}
int get(int x) {
int res = 0;
for(; x; x -= x & -x) res += t[x];
return res;
}
};
int n, m, a[maxn], b[maxn], t[maxn];
int cnt[maxn];
ll res;
vector<pii> query;
vector<int> vals;
void compress() {
FOR(i, 1, m) vals.push_back(t[i]);
sort(ALL(vals));
vals.resize(unique(ALL(vals)) - vals.begin());
FOR(i, 1, m) t[i] = lower_bound(ALL(vals), t[i]) - vals.begin() + 1;
}
bool cmp(pii &A, pii &B) {
return A.fi > B.fi;
}
int main() {
ios_base::sync_with_stdio(0); cin.tie(0 ); cout.tie(0);
cin >> n >> m;
FOR(i, 1, n)
cin >> a[i] >> b[i];
FOR(i, 1, m) cin >> t[i];
compress();
SegmentTree st(m);
FenwickTree ft(m);
FOR(i, 1, m) st.update(t[i], i);
FOR(i, 1, n) {
int l = lower_bound(ALL(vals), min(a[i], b[i])) - vals.begin() + 1;
int r = lower_bound(ALL(vals), max(a[i], b[i])) - vals.begin();
int p = st.get(l, r);
if(p + 1 <= m) query.push_back({ p + 1, i });
if(p > 0 && a[i] <= b[i]) swap(a[i], b[i]);
}
sort(ALL(query), cmp);
int j = m + 1;
for(pii x : query) {
while(j - 1 >= x.fi) ft.update(t[--j], 1);
int p = lower_bound(ALL(vals), max(a[x.se], b[x.se])) - vals.begin() + 1;
cnt[x.se] = ft.get(m) - ft.get(p - 1);
}
FOR(i, 1, n) if(cnt[i] & 1) swap(a[i], b[i]);
FOR(i, 1, n) res += a[i];
cout << res;
return 0;
}
