#include <bits/stdc++.h>
#pragma GCC target("avx2")
#pragma GCC optimize("O3,unroll-loops")
using namespace std;
#define int long long
#define pii pair<int,int>
#define ff first
#define ss second
#define sp << " " <<
#define all(cont) cont.begin(),cont.end()
#define vi vector<int>
const int inf = 1e17,N = 2e6+1,MOD = (1LL<<61)-1,B = 23;
vi v;
int idx(int x) {
return upper_bound(all(v),x)-v.begin();
}
struct ST {
vi t;
ST(int nn) {
t.assign(4*nn+1,0);
}
void update(int node,int l,int r,int p,int v) {
if (l == r) {
t[node] = max(t[node],v);
return;
}
int m = (l+r) >> 1;
if (p <= m) update(2*node,l,m,p,v);
else update(2*node+1,m+1,r,p,v);
t[node] = max(t[2*node],t[2*node+1]);
}
int query(int node,int l,int r,int L,int R) {
if (l > R || r < L) return 0;
if (l >= L && r <= R) return t[node];
int m = (l+r) >> 1;
return max(query(2*node,l,m,L,R),query(2*node+1,m+1,r,L,R));
}
};
struct FT {
vi bit;
int n;
FT(int nn) {
n = nn;
bit.assign(n+1,0);
}
void put(int p,int v) {
p = n-p+1;
for (int i = p;i<=n;i+=i&-i) bit[i]+=v;
}
int get(int p) {
p = n-p+1;
int ans = 0;
for (int i = p;i>0;i-=i&-i) ans+=bit[i];
return ans;
}
};
void solve() {
int n,q;
cin >> n >> q;
vector<pii> ps(n+1);
vi fs(n+1),sec(n+1),mn(n+1),mx(n+1);
for (int i=1;i<=n;i++) {
cin >> ps[i].ff >> ps[i].ss;
v.push_back(ps[i].ff);
v.push_back(ps[i].ss);
}
vi qs(q+1);
for (int i=1;i<=q;i++) {
cin >> qs[i];
v.push_back(qs[i]);
}
sort(all(v));
v.erase(unique(all(v)),v.end());
sort(ps.begin()+1,ps.end(),[&](pii p1,pii p2) {
return max(p1.ff,p1.ss) > max(p2.ff,p2.ss);
});
for (int i=1;i<=n;i++) {
fs[i] = ps[i].ff,sec[i] = ps[i].ss;
mn[i] = min(fs[i],sec[i]),mx[i] = max(fs[i],sec[i]);
}
for (int i=1;i<=n;i++) ps[i].ff = idx(ps[i].ff),ps[i].ss = idx(ps[i].ss);
for (int i=1;i<=q;i++) qs[i] = idx(qs[i]);
int sz = v.size();
ST st(sz);
FT ft(q);
priority_queue<pii> topush;
for (int i=1;i<=q;i++) {
st.update(1,1,sz,qs[i],i);
topush.push({qs[i],i});
}
int ans = 0;
for (int i=1;i<=n;i++) {
while (!topush.empty() && topush.top().ff >= max(ps[i].ff,ps[i].ss)) {
ft.put(topush.top().ss,1);
topush.pop();
}
int lst = st.query(1,1,sz,min(ps[i].ff,ps[i].ss),max(ps[i].ff,ps[i].ss)-1);
int swp = ft.get(lst+1);
if (!lst) {
if (swp%2) ans+=sec[i];
else ans+=fs[i];
}
else {
if (swp%2) ans+=mn[i];
else ans+=mx[i];
}
}
cout << ans << '\n';
}
int32_t main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#ifdef Dodi
freopen("in.txt","r",stdin);
freopen("out.txt","w",stdout);
#endif
int t = 1;
//cin >> t;
while (t --> 0) solve();
}
