#include <bits/stdc++.h>
#pragma GCC optimize("O3")
#define int long long
#define ll long long
#define pb push_back
#define fi first
#define se second
#define lf (id<<1)
#define rg ((id<<1)|1)
#define md ((l+r)>>1)
#define ld long double
using namespace std;
typedef pair<int,int> pii;
typedef pair<char,char> pcc;
typedef pair<int,pii> ipii;
typedef pair<pii,pii> ipiii;
const int MAXN = 6e5+10;
const int MAXA = 1e6;
const int INF = 1e18+10;
const int MOD = 1e9+7;
const int LOG = 20;
const ld EPS = 1e-12;
int n, k, a[MAXN], b[MAXN], q[MAXN];
int st[MAXN][LOG+5], val[MAXN];
vector<int> cc;
vector <pii> vec[MAXN];
int QUE(int l, int r){
if(l>r) return 0;
int len = log2(r-l+1);
return max(st[l][len], st[r-(1<<len)+1][len]);
}
struct seg {
int st[2*MAXN];
int que(int x){
int te = 0;
for(; x>=1; x-=(x&(-x))) te += st[x];
return te;
}
void upd(int x, int p){
for(; x<=2*MAXN-20; x+=(x&(-x))) st[x] += p;
}
} A;
signed main(){
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
cin >> n >> k;
cc.pb(-1);
for(int i=1; i<=n; i++){
cin >> a[i]>>b[i];cc.pb(a[i]);cc.pb(b[i]);
}
for(int i=1; i<=k; i++){
cin >> q[i]; cc.pb(q[i]);
}
sort(cc.begin(), cc.end());
cc.resize(unique(cc.begin(), cc.end()) - cc.begin());
for(int i=1; i<=k; i++){
int id = lower_bound(cc.begin(), cc.end(), q[i]) - cc.begin();
st[id][0] = i;
}
for(int j=1; j<LOG; j++)
for(int i=1; i+(1<<j)-1<=cc.size(); i++)
st[i][j] = max(st[i][j-1], st[i+(1<<(j-1))][j-1]);
int ans = 0;
for(int i=1; i<=n; i++){
int le = lower_bound(cc.begin(), cc.end(), min(a[i],b[i])) - cc.begin();
int ri = lower_bound(cc.begin(), cc.end(), max(a[i],b[i])) - cc.begin() - 1;
int las = QUE(le, ri);
// cout <<i << ' '<< las <<"las\n";
if(las == 0) vec[0].pb({max(le,ri), i});
else vec[las+1].pb({max(le,ri), i});
}
for(int i=k; i>=1; i--){
int id = lower_bound(cc.begin(), cc.end(), q[i]) - cc.begin();
A.upd(id, 1);
for(auto [val, idx] : vec[i]){
int tot = k-i+1 - A.que(val);
// cout << idx << " idx\n";
if(tot%2 == 0){
ans += max(a[idx], b[idx]);
// cout << max(a[idx], b[idx]) << "max\n";
} else {
ans += min(a[idx],b[idx]);
// cout << min(a[idx], b[idx]) << "min\n";
}
}
}
for(auto [val, idx] : vec[0]){
int tot = k - A.que(val);
// cout << idx << " idx\n";
if(tot%2 == 0){
ans += a[idx];
// cout << a[idx] << "a\n";
} else {
ans += b[idx];
// cout << b[idx] << "b\n";
}
}
cout << ans << '\n';
}
