#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define X first
#define Y second
#define SZ(x) int(x.size())
#define all(x) x.begin(), x.end()
#define mins(a,b) (a = min(a,b))
#define maxs(a,b) (a = max(a,b))
#define pb push_back
#define Mp make_pair
#define kill(x) {cout << (x) << '\n'; exit(0);}
#define killt(x) {cout << (x) << '\n'; return;}
#define lc id<<1
#define rc lc|1
#define mid ((l+r)/2)
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
const ll INF = 1e9 + 23;
const ll MOD = 1e9 + 7;
const int MXN = 2e5 + 5;
const int MXM = 6e5 + 5;
const int LOG = 23;
int n, k, a[MXN], b[MXN], t[MXN];
vector<int> cmp;
int GI(int x) {
return lower_bound(all(cmp), x)-cmp.begin();
}
int m, seg[MXM<<2];
void Build_seg(int l=0, int r=m, int id=1) {
seg[id] = 0;
if(r-l == 1) return;
Build_seg(l, mid, lc);
Build_seg(mid, r, rc);
}
void Upd_seg(int p, int x, int l=0, int r=m, int id=1) {
if(r-l == 1) {
seg[id] = x;
return;
}
if(p<mid) Upd_seg(p, x, l, mid, lc);
else Upd_seg(p, x, mid, r, rc);
seg[id] = max(seg[lc], seg[rc]);
}
int Get_seg(int s, int e, int l=0, int r=m, int id=1) {
if(s <= l && r <= e) return seg[id];
return max(
(s<mid ? Get_seg(s, e, l, mid, lc) : 0),
(e>mid ? Get_seg(s, e, mid, r, rc) : 0)
);
}
vector<int> mrg[MXN<<2];
void merge_sort(int l=1, int r=k+1, int id=1) {
if(r-l == 1) {
mrg[id] = {t[l]};
return;
}
merge_sort(l, mid, lc);
merge_sort(mid, r, rc);
int i=0, j=0;
while(i<SZ(mrg[lc]) && j<SZ(mrg[rc]))
if(mrg[lc][i]<mrg[rc][j]) mrg[id].pb(mrg[lc][i++]);
else mrg[id].pb(mrg[rc][j++]);
while(i<SZ(mrg[lc])) mrg[id].pb(mrg[lc][i++]);
while(j<SZ(mrg[rc])) mrg[id].pb(mrg[rc][j++]);
}
int Get_parity(int s, int e, int x, int l=1, int r=k+1, int id=1) {
if(s <= l && r <= e) {
int pos = lower_bound(all(mrg[id]), x)-mrg[id].begin();
return (SZ(mrg[id])-pos)&1;
}
if(e<=mid) return Get_parity(s,e,x, l, mid, lc);
if(s>=mid) return Get_parity(s,e,x, mid, r, rc);
return Get_parity(s,e,x, l, mid, lc)^Get_parity(s,e,x, mid, r, rc);
}
void Main() {
cin >> n >> k;
for(int i=1; i<=n; i++) {
cin >> a[i] >> b[i];
cmp.pb(a[i]);
cmp.pb(b[i]);
}
for(int i=1; i<=k; i++) {
cin >> t[i];
cmp.pb(t[i]);
}
sort(all(cmp));
cmp.resize(unique(all(cmp))-cmp.begin());
m = SZ(cmp);
for(int i=1; i<=n; i++) {
a[i] = GI(a[i]);
b[i] = GI(b[i]);
}
Build_seg();
for(int i=1; i<=k; i++) {
t[i] = GI(t[i]);
Upd_seg(t[i], i);
}
merge_sort();
ll ans=0;
for(int i=1; i<=n; i++) {
if(a[i] != b[i]) {
int pos = Get_seg(min(a[i], b[i]), max(a[i], b[i]));
if(pos) {
vector<int> vec = {max(a[i], b[i]), min(a[i], b[i])};
ans += cmp[vec[pos<k && Get_parity(pos+1, k+1, max(a[i], b[i]))]];
}
else {
vector<int> vec = {a[i], b[i]};
ans += cmp[vec[Get_parity(1, k+1, max(a[i], b[i]))]];
}
}
else ans += cmp[a[i]];
}
cout << ans << '\n';
}
int32_t main() {
cin.tie(0); cout.tie(0); ios_base::sync_with_stdio(0);
int T = 1;
// cin >> T;
while(T--) Main();
return 0;
}
