#include <bits/stdc++.h>
using namespace std;
#define rep(i, l, r) for(auto i=l; i<r; i++)
#define all(v) v.begin(), v.end()
#define nn '\n'
using vi = vector<int>;
using ll = long long;
struct node{
int val = 0, c = -1, c2 = -1;
};
int nxt=2;
vector<node> seg((int)5e6+3);
int intersec(int l, int r, int l2, int r2){
return min(r, r2) - max(l, l2) + 1;
}
int query(int ql, int qr, const node &cur, auto const &comb, int id, int l=1, int r=1e9){
int mid = (l + r) / 2, res = id;
if(intersec(l, r, ql, qr) == r - l + 1)
return cur.val;
if(cur.c != -1 && intersec(l, mid, ql, qr) > 0)
comb(res, query(ql, qr, seg[cur.c], comb, id, l, mid));
if(cur.c2 != -1 && intersec(mid+1, r, ql, qr) > 0)
comb(res, query(ql, qr, seg[cur.c2], comb, id, mid+1, r));
return res;
}
void upd(int pos, int nval, node &cur, auto const &comb, int id, int l=1, int r=1e9){
int mid = (l + r) / 2;
if(l == r){
if(nval >= 0) cur.val = nval;
else cur.val += -nval;
return;
}
cur.val = id;
if(intersec(l, mid, pos, pos) == 1){
if(cur.c == -1) cur.c = nxt++;
seg[cur.c].val = id;
upd(pos, nval, seg[cur.c], comb, id, l, mid);
}
else{
if(cur.c2 == -1) cur.c2 = nxt++;
seg[cur.c2].val = id;
upd(pos, nval, seg[cur.c2], comb, id, mid+1, r);
}
if(cur.c != -1) comb(cur.val, seg[cur.c].val);
if(cur.c2 != -1) comb(cur.val, seg[cur.c2].val);
}
void add(int &a, int b){ a += b; }
void cmax(int &a, int b){ a = max(a, b); }
void updmx(int pos, int nval){
upd(pos, nval, seg[0], cmax, -1);
}
void updcnt(int pos){
upd(pos, -1, seg[1], add, 0);
}
int querymx(int l, int r){
return query(l, r, seg[0], cmax, -1, 1);
}
int querycnt(int l, int r){
return query(l, r, seg[1], add, 0);
}
void solve(){
seg[0].val = -1;
seg[1].val = 0;
int n, k;
cin >> n >> k;
vector<int> a(n), b=a, t(k);
rep(i, 0, n) cin >> a[i] >> b[i];
rep(i, 0, k){
cin >> t[i];
updmx(t[i], i);
}
vi ind[k+1], flip(n);
rep(i, 0, n){
if(a[i] > b[i]){ swap(a[i], b[i]); flip[i] = 1; }
int q = querymx(a[i], b[i]-1);
ind[q+1].push_back(i);
}
for(int i=k-1; i>=0; i--){
updcnt(t[i]);
for(int j : ind[i+1])
flip[j] = 1 - querycnt(b[j], 1e9) % 2;
}
for(int j : ind[0])
flip[j] ^= querycnt(b[j], 1e9) % 2;
ll sum = 0;
rep(i, 0, n){
if(flip[i]) sum += b[i];
else sum += a[i];
}
cout << sum;
}
int main(){
ios::sync_with_stdio(0);
cin.tie(0);
solve();
}
