#include <bits/stdc++.h>
#define FOR(i,x,n) for(int i=x; i<n; i++)
#define F0R(i,n) FOR(i,0,n)
#define ROF(i,x,n) for(int i=n-1; i>=x; i--)
#define R0F(i,n) ROF(i,0,n)
#define WTF cout << "WTF" << endl
#define IOS ios::sync_with_stdio(false); cin.tie(0)
#define F first
#define S second
#define pb push_back
#define ALL(x) x.begin(), x.end()
#define RALL(x) x.rbegin(), x.rend()
using namespace std;
typedef long long LL;
typedef pair<int, int> PII;
typedef pair<LL, LL> PLL;
typedef vector<int> VI;
typedef vector<LL> VLL;
typedef vector<PII> VPII;
typedef vector<PLL> VPLL;
const int N = 2e5 + 7;
const int ALPHA = 27;
const int INF = 1e9 + 7;
const int MOD = 1e9 + 7;
const int LOG = 22;
struct Card {
int a, b, id;
bool ch = 0;
inline bool operator < (const Card other) {
return a < other.a;
}
} ns[N];
int n, k;
int stree[N << 2], mtree[N << 2];
PII ks[N];
#define lc now << 1
#define rc now << 1 | 1
void mchange(int id, int val, int now = 1, int ls = 0, int rs = k - 1) {
if (ls == rs) {
mtree[now] = val;
return;
}
int mid = (ls + rs) >> 1;
if (id <= mid) mchange(id, val, lc, ls, mid);
else mchange(id, val, rc, mid + 1, rs);
mtree[now] = min(mtree[lc], mtree[rc]);
return;
}
int descend(int val, int now = 1, int ls = 0, int rs = k - 1) {
if (mtree[now] >= val) return INF;
if (ls == rs) return ls;
int mid = (ls + rs) >> 1;
int case1 = descend(val, rc, mid + 1, rs);
return (case1 == INF ? descend(val, lc, ls, mid) : case1);
}
int sbuild(int now = 1, int ls = 0, int rs = k - 1) {
if (ls == rs) return stree[now] = 1;
int mid = (ls + rs) >> 1;
return stree[now] = sbuild(lc, ls, mid) + sbuild(rc, mid + 1, rs);
}
int get(int lq, int rq, int now = 1, int ls = 0, int rs = k - 1) {
if (rq < lq || rq < ls || rs < lq) return 0;
if (lq <= ls && rs <= rq) return stree[now];
int mid = (ls + rs) >> 1;
return get(lq, rq, lc, ls, mid) + get(lq, rq, rc, mid + 1, rs);
}
void schange(int id, int val, int now = 1, int ls = 0, int rs = k - 1) {
if (ls == rs) {
stree[now] = val;
return;
}
int mid = (ls + rs) >> 1;
if (id <= mid) schange(id, val, lc, ls, mid);
else schange(id, val, rc, mid + 1, rs);
stree[now] = stree[lc] + stree[rc];
return;
}
int main() {
IOS;
cin >> n >> k;
F0R(i, n) {
cin >> ns[i].a >> ns[i].b;
if (ns[i].a > ns[i].b) {
swap(ns[i].a, ns[i].b);
ns[i].ch = 1;
}
}
F0R(i, k) {
cin >> ks[i].F;
ks[i].S = i;
}
F0R(i, k) mchange(i, ks[i].F);
sbuild();
sort(ks, ks + k);
sort(ns, ns + n);
/*cout << "descend(9) = " << descend(9) << endl;
cout << "get(2, 2) = " << get(2, 2) << endl;
F0R(i, n) {
cout << ns[i].a << ' ' << ns[i].b << " - " << endl;
}*/
int ptr = 0;
LL ans = 0;
F0R(i, n) {
while(ptr < k && ks[ptr].F < ns[i].a) {
mchange(ks[ptr].S, INF);
schange(ks[ptr].S, 0);
ptr++;
}
int pl = descend(ns[i].b);
if (pl == INF) {
int sum = get(0, k - 1);
if ((sum & 1) ^ (ns[i].ch)) ans += ns[i].b;
else ans += ns[i].a;
continue;
}
int sum = get(pl + 1, k - 1);
if (sum & 1) ans += ns[i].a;
else ans += ns[i].b;
//cout << "for card " << ns[i].a << ' ' << ns[i].b << " added : " << (sum & 1 ? ns[i].a : ns[i].b) << endl;
}
cout << ans;
}
