#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 1e6 + 5;
int n, k, a[N], b[N], t[N];
int m, lst[N], lg[N], ot[N], oa[N];
int mx[N][25];
vector<int> rrh;
void init(){
for(int i = 1; i <= n; i++){
rrh.push_back(a[i]);
rrh.push_back(b[i]);
}
for(int i = 1; i <= k; i++) rrh.push_back(t[i]);
sort(rrh.begin(), rrh.end());
rrh.erase(unique(rrh.begin(), rrh.end()), rrh.end());
for(int i = 1; i <= n; i++){
a[i] = lower_bound(rrh.begin(), rrh.end(), a[i]) - rrh.begin() + 1;
b[i] = lower_bound(rrh.begin(), rrh.end(), b[i]) - rrh.begin() + 1;
}
for(int i = 1; i <= k; i++){
t[i] = lower_bound(rrh.begin(), rrh.end(), t[i]) - rrh.begin() + 1;
mx[t[i]][0] = max(mx[t[i]][0], i);
}
m = rrh.size();
for(int j = 1; j <= 20; j++)
for(int i = 1; i + (1 << j) - 1 <= m; i++)
mx[i][j] = max(mx[i][j - 1], mx[i + (1 << j - 1)][j - 1]);
for(int i = 2; i <= m; i++) lg[i] = lg[i/2] + 1;
}
int get(int l, int r){
if(l > r) return 0;
int k = lg[r - l + 1];
return max(mx[l][k], mx[r - (1 << k) + 1][k]);
}
namespace bit{
int bit[N];
void update(int i, int y){
for(; i <= k; i += i & -i) bit[i] += y;
}
int pref(int i){
int res = 0;
for(; i > 0; i -= i & -i) res += bit[i];
return res;
}
int get(int l, int r){
if(l > r) return 0;
return pref(r) - pref(l - 1);
}
};
void solve(){
init();
for(int i = 1; i <= n; i++){
lst[i] = get(min(a[i], b[i]), max(a[i], b[i]) - 1);
if(lst[i] && a[i] < b[i]) swap(a[i], b[i]);
lst[i] += 1;
}
iota(ot + 1, ot + k + 1, 1);
iota(oa + 1, oa + n + 1, 1);
sort(ot + 1, ot + k + 1, [&](int i, int j){
return t[i] > t[j];
});
sort(oa + 1, oa + n + 1, [&](int i, int j){
return a[i] > a[j];
});
int res = 0;
for(int i = 1, j = 0; i <= n; i++){
while(j < k && t[ot[j + 1]] >= max(a[oa[i]], b[oa[i]])){
j += 1;
bit::update(ot[j], 1);
}
int cnt = bit::get(lst[oa[i]], k);
if(cnt & 1) swap(a[oa[i]], b[oa[i]]);
res += rrh[a[oa[i]] - 1];
}
cout << res << "\n";
}
int32_t main(){
cin.tie(0)->sync_with_stdio(0);
cin >> n >> k;
for(int i = 1; i <= n; i++) cin >> a[i] >> b[i];
for(int i = 1; i <= k; i++) cin >> t[i];
AC::solve();
return 0;
}
