#include <bits/stdc++.h>
using namespace std;
#define fi first
#define sc second
const int MAXN = 2*1e5+5;
pair<int,int> p[MAXN], t[MAXN];
int mx[MAXN*4], id[MAXN], bit[MAXN], k;
bool cmp(pair<int,int> a, pair<int,int> b){return max(a.fi,a.sc) < max(b.fi,b.sc);}
void update(int node, int l, int r, int i, int x){
if(i < l || r < i)return;
if(l == r){
mx[node] = x;
return;
}
int mid = (l+r)/2 , e = node*2, d = node*2+1;
update(e,l,mid,i,x); update(d,mid+1,r,i,x);
mx[node] = max(mx[e], mx[d]);
}
int bb(int node, int l, int r, int x){
if(l == r){
if(mx[node] < x)return -1;
return l;
}
int mid = (l+r)/2 , e = node*2, d = node*2+1;
if(mx[d] >= x)return bb(d,mid+1,r,x);
return bb(e,l,mid,x);
}
void updateB(int i, int x){
for(; i <= k; i += i&-i)
bit[i] += x;
}
int queryB(int i){
if(i < 1)return 0;
int ans = 0;
for(; i > 0; i -= i&-i)
ans += bit[i];
return ans;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
int n; cin>>n>>k;
for(int i = 1; i <= n; i++)cin>>p[i].fi>>p[i].sc;
sort(p+1,p+1+n, cmp);
for(int i = 1; i <= k; i++){
cin>>t[i].fi;
t[i].sc = i;
}
sort(t+1,t+1+k);
int cur = 1;
for(int i = 1; i <= k; i++){
while(cur <= n && max(p[cur].fi,p[cur].sc) <= t[i].fi){
id[cur] = bb(1,1,k, min(p[cur].fi,p[cur].sc));
cur++;
}
update(1,1,k, t[i].sc, t[i].fi);
}
while(cur <= n){
id[cur] = bb(1,1,k, min(p[cur].fi,p[cur].sc));
cur++;
}
cur = n;
int ans = 0;
for(int i = k; i >= 1; i--){
while(cur > 0 && max(p[cur].fi,p[cur].sc) > t[i].fi){
int x = queryB(k) - queryB(id[cur]);
if(id[cur] == -1){
if(x%2 == 0)ans += p[cur].fi;
else ans += p[cur].sc;
}else{
if(x%2 == 0)ans += max(p[cur].fi, p[cur].sc);
else ans += min(p[cur].fi, p[cur].sc);
}
cur--;
}
updateB(t[i].sc, 1);
}
while(cur > 0){
int x = queryB(k) - queryB(id[cur]);
if(id[cur] == -1){
if(x%2 == 0)ans += p[cur].fi;
else ans += p[cur].sc;
}else{
if(x%2 == 0)ans += max(p[cur].fi, p[cur].sc);
else ans += min(p[cur].fi, p[cur].sc);
}
cur--;
}
cout<<ans<<"\n";
}
