#include <bits/stdc++.h>
#define ff(i,a,b) for(int (i) = (a); (i) <= (b); ++(i))
#define fb(i,a,b) for(int (i) = (a); (i) >= (b); --(i))
#define pii pair<int,int>
#define xx first
#define yy second
#define pb push_back
using namespace std;
typedef long long ll;
int n,k;
pii niz[200005];
pii val[200005];
int seg[4 * 200005];
void init(int node, int l, int r){
if(l == r){
seg[node] = val[l].yy;
return;
}
int mid = (l + r) / 2;
init(node * 2, l, mid);
init(node * 2 + 1, mid + 1, r);
seg[node] = max(seg[node * 2], seg[node * 2 + 1]);
}
int kveri(int node, int l, int r, int levo, int desno){
if(l > r || levo > desno || l > desno || levo > r)return 0;
if(l >= levo && r <= desno)return seg[node];
int mid = (l + r) / 2;
return max(kveri(node * 2, l, mid, levo, desno), kveri(node * 2 + 1, mid + 1, r, levo, desno));
}
vector<int> kv[200005];
bool cmp2(pii a, pii b){
return a.yy < b.yy;
}
map<int,int>poj;
int bit[400005];
pii orig[400005];
void update(int x){
while(x>0){
bit[x]++;
x -= (x&-x);
}
}
int query(int x){
int ans = 0;
while(x<=400000){
ans += bit[x];
x += (x&-x);
}
return ans;
}
int main()
{
ios_base::sync_with_stdio(false);
cin >> n >> k;
ff(i,1,n){
cin >> niz[i].xx;
cin >> niz[i].yy;
orig[i] = niz[i];
}
ff(i,1,k){
cin >> val[i].xx;
val[i].yy = i;
}
sort(val + 1, val + k + 1);
init(1,1,n);
ff(i,1,n){
int mn = min(niz[i].xx,niz[i].yy);
int mx = max(niz[i].xx,niz[i].yy);
mx--;
int l = 1;
int r = k;
int levo = -1;
if(val[k].xx >= mn){
while(l < r){
int mid = (l + r) / 2;
if(val[mid].xx >= mn)r = mid;
else l = mid + 1;
}
levo = l;
}
int desno = -1;
l = 1;
r = k;
if(val[1].xx <= mx){
while(l < r){
int mid = (l + r + 1) / 2;
if(val[mid].xx <= mx)l = mid;
else r = mid - 1;
}
desno = l;
}
if(desno == -1 || levo == -1 || levo > desno){
//cout << i << "\n";
kv[1].pb(i);
continue;
}
if(levo <= desno){
kv[kveri(1,1,k,levo,desno)].pb(i);
if(niz[i].xx <= niz[i].yy)swap(niz[i].xx, niz[i].yy);
continue;
}
}
sort(val + 1, val + k + 1, cmp2);
vector<int> svi;
ff(i,1,k)svi.pb(val[i].xx);
ff(i,1,n){
svi.pb(niz[i].xx);
svi.pb(niz[i].yy);
}
sort(svi.begin(), svi.end());
int last = -1;
int br=1;
for(auto c:svi){
if(c == last)continue;
poj[c] = br;
br++;
last = c;
}
ff(i,1,n){
niz[i].xx = poj[niz[i].xx];
niz[i].yy = poj[niz[i].yy];
}
ff(i,1,k)val[i].xx = poj[val[i].xx];
fb(i,k,1){
update(val[i].xx);
for(auto c:kv[i]){
int sta = query(max(niz[c].xx, niz[c].yy));
if(sta%2 == 1)swap(orig[c].xx,orig[c].yy);
}
}
ll sum = 0;
ff(i,1,n)sum += orig[i].xx;
cout << sum << "\n";
return 0;
}
