#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
template<class T> bool maximize(T &a, const T &b){ return (a < b ? a = b, 1 : 0); }
template<class T> bool minimize(T &a, const T &b){ return (a > b ? a = b, 1 : 0); }
#define fi first
#define se second
#define pb push_back
#define ii pair<int, int>
#define all(x) x.begin(), x.end()
#define TASK "nonsense"
/// end of template ///
const int N = 2e5 + 25;
const int K = 2e5 + 25;
int n,k,a[N],b[N],t[N];
namespace sub1
{
bool check()
{
return (n<=1000 && k<=1000);
}
void solve()
{
for (int tri=1; tri<=k; ++tri)
{
int cur=t[tri];
for (int i=1; i<=n; ++i) if (a[i]<=cur) swap(a[i],b[i]);
}
ll sum=0;
for (int i=1; i<=n; ++i) sum+=a[i];
cout<<sum;
}
}
namespace subfull
{
const int M = 6e5 + 65;
const int inf = INT_MAX/10;
vector<int> v;
int m,lst[M],lg[M],rmq[M][20];
int getRmq(int l, int r)
{
if (l>r) return 0;
int k=lg[r-l+1];
int cur=max(rmq[l][k],rmq[r-(1<<k)+1][k]);
// cout<<l<<' '<<r<<' '<<k<<' '<<cur<<'\n';
return max(cur,0);
}
bool bit[M];
void add(int x)
{
x=m-x+1;
while (x<=m)
{
bit[x]^=1;
x+=x&-x;
}
}
bool get(int x)
{
x=m-x+1;
bool ans=0;
while (x>=1)
{
ans^=bit[x];
x-=x&-x;
}
return ans;
}
vector<ii> query[M];
int oldA[N],oldB[N];
bool exchange[N];
void solve()
{
for (int i=1; i<=n; ++i) v.pb(a[i]),v.pb(b[i]);
for (int i=1; i<=k; ++i) v.pb(t[i]);
sort(all(v)); v.erase(unique(all(v)),v.end());
for (int i=1; i<=n; ++i)
{
oldA[i]=a[i];
oldB[i]=b[i];
a[i]=lower_bound(all(v),a[i])-v.begin()+1;
b[i]=lower_bound(all(v),b[i])-v.begin()+1;
}
for (int i=1; i<=k; ++i)
{
t[i]=lower_bound(all(v),t[i])-v.begin()+1;
}
m=(int)v.size();
for (int i=1; i<M; ++i) lst[i]=-inf;
for (int i=1; i<=k; ++i) lst[t[i]]=i;
for (int i=1; i<=m; ++i) rmq[i][0]=lst[i];
// cout<<lst[8]<<' '<<rmq[8][0]<<'\n';
for (int j=1; j<20; ++j) for (int i=1; i+(1<<j)-1<=m; ++i)
{
rmq[i][j]=max(rmq[i][j-1],rmq[i+(1<<(j-1))][j-1]);
}
// cout<<rmq[8][0];
// return;
for (int i=2; i<=m; ++i) lg[i]=lg[i>>1]+1;
for (int i=1; i<=n; ++i)
{
int l=min(a[i],b[i]),r=max(a[i],b[i]);
int last=getRmq(l,r-1);
if (last!=0)
{
exchange[i]=(r!=a[i]);
a[i]=r;
b[i]=l;
}
// cout<<i<<' '<<last<<'\n';
query[last+1].pb({r,i});
}
for (int tri=k+1; tri>=1; --tri)
{
if (tri<=k) add(t[tri]);
for (ii &cm : query[tri])
{
bool cur=get(cm.fi);
if (cur==1)
{
int id=cm.se;
exchange[id]^=1;
}
}
}
ll ans=0;
for (int i=1; i<=n; ++i)
{
if (exchange[i]) swap(oldA[i],oldB[i]);
ans+=oldA[i];
}
// for (int i=1; i<=n; ++i) cout<<a[i]<<' ';
// cout<<'\n';
cout<<ans;
}
}
void solve()
{
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];
if (sub1::check()) return void(sub1::solve());
return void(subfull::solve());
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
// freopen(TASK".inp","r",stdin);
// freopen(TASK".out","w",stdout);
int testcase=1;
// cin>>testcase;
while (testcase--)
solve();
// #define TIME (1.0 * clock() / CLOCKS_PER_SEC)
// cerr << "Time elapsed: " << TIME << " s.\n";
return 0;
}
