#include <bits/stdc++.h>
using namespace std;
const int N=2e5;
const int inf = 1e9+7;
struct segtree
{
int val=0;
int lazy=0;
int mx,mn;
}st[4*N+1];
struct card
{
int l, r;
int s=0;
bool operator < (const card & o) const
{
if(r==o.r) return l < o.l;
return r < o.r;
}
}a[N+1],tmp;
int s[N+1], id[N+1];
void Set(int x, int low, int hi, int i, int s, int k)
{
if(low==hi)
{
st[x].mn=k;
st[x].mx=k;
st[x].val=s;
return;
}
int mid = low+hi>>1;
if(i<=mid) Set(x*2,low,mid,i,s,k);
else Set(x*2+1,mid+1,hi,i,s,k);
st[x].mx = max(st[x*2].mx, st[x*2+1].mx);
st[x].mn = min(st[x*2].mn, st[x*2+1].mn);
}
//lazy=0 -> 0
//lazy=1 -> ^1
//lazy=2 ->|1
//lazy=3 -> &1
void operate(int& a, int b)
{
if(b==1) {a^=1; return;}
if(b==2) {a=1; return;}
if(b==3) {a=0; return;}
}
void change(int& a, int b)
{
if(a==0) {a=b; return;}
if(b==2 || b==3) {a=b; return;}
if(a==1 && b==1) {a=0; return;}
if(a==2 && b==1) {a=3; return;}
if(a==3 && b==1) {a=2; return;}
}
void push(int x)
{
if(st[x].lazy==0) return;
operate(st[x*2].val,st[x].lazy);
operate(st[x*2+1].val,st[x].lazy);
change(st[x*2].lazy,st[x].lazy);
change(st[x*2+1].lazy,st[x].lazy);
st[x].lazy=0;
}
void updateXOR(int x, int low, int hi, int i , int j)
{
if(low > hi || low > j || hi<i) return;
if(low>=i && hi<=j)
{
st[x].val^=1;
if(st[x].lazy==0) {st[x].lazy=1; return;}
if(st[x].lazy==1) {st[x].lazy=0; return;}
if(st[x].lazy==2) {st[x].lazy=3; return;}
if(st[x].lazy==3) {st[x].lazy=2; return;}
}
int mid = low+hi>>1;
push(x);
updateXOR(x*2,low,mid,i,j);
updateXOR(x*2+1,mid+1,hi,i,j);
}
void updateOR(int x, int low, int hi, int i, int j, int k)
{
if(low > hi || low > j || hi<i || st[x].mn>k) return;
if(low>=i && hi<=j)
{
if(st[x].mx<=k)
{
st[x].val=1;
st[x].lazy=2;
return;
}
}
int mid =low+hi>>1;
push(x);
updateOR(x*2,low,mid,i,j,k);
updateOR(x*2+1,mid+1,hi,i,j,k);
}
int get(int x, int low, int hi, int i)
{
if(low==hi) return st[x].val;
int mid = low+hi>>1;
push(x);
if(i<=mid) return get(x*2,low,mid,i);
return get(x*2+1,mid+1,hi,i);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
int n,k;
cin >> n >> k;
for(int i=1;i<=n;++i)
{
cin >> a[i].l >> a[i].r;
if(a[i].l > a[i].r)
{
swap(a[i].l,a[i].r);
a[i].s=1;
}
}
sort(a+1,a+n+1);
for(int i=1;i<=n;++i)
{
Set(1,1,n,i,a[i].s,a[i].l);
}
while(k--)
{
int x;
cin >> x;
tmp.l=inf;
tmp.r=x;
int p = upper_bound(a+1,a+n+1,tmp)-a-1;
updateXOR(1,1,n,1,p);
updateOR(1,1,n,p+1,n,x);
//cout << p << " " << get(1,1,n,2) << '\n';
}
long long ans=0;
for(int i=1;i<=n;++i)
{
int x = get(1,1,n,i);
//cout << a[i].l << " " << a[i].r << " ";
//cout << x << "\n";
if(x==1) ans+=(long long)a[i].r;
else ans+=(long long)a[i].l;
}
//cout << '\n';
cout << ans;
}
