#include<stdio.h>
#include<algorithm>
using namespace std;
int p,cnt,w,t,n,k,a[200010],b[200010],c[200010],tree[2000010],tree2[2000010],sw[200010],a2[200010],b2[200010];
long long sum;
struct data
{
int x,y;
bool operator<(const data&r)const
{
return x<r.x;
}
}arr[600010];
data pos[600010];
void update(int x,int p)
{
x+=t-1; tree[x]=p; x/=2;
while(x){
tree[x]=max(tree[x*2],tree[x*2+1]);
x/=2;
}
}
void update2(int x)
{
while(x<=t){
tree2[x]++;
x+=x&(-x);
}
}
int query(int x,int y,int k,int s,int e)
{
if(x>e || y<s) return 0;
if(s<=x && y<=e) return tree[k];
return max(query(x,(x+y)/2,k*2,s,e),query((x+y)/2+1,y,k*2+1,s,e));
}
int query2(int x)
{
int hap=0;
while(x){
hap+=tree2[x];
x-=x&(-x);
}
return hap;
}
int main()
{
int i,j,s;
scanf("%d %d",&n,&k);
for(i=1;i<=n;i++){
scanf("%d %d",&a[i],&b[i]);
if(a[i]>b[i]) swap(a[i],b[i]), sw[i]=1;
a2[i]=a[i], b2[i]=b[i];
arr[++w].x=a[i]; arr[w].y=i*2;
arr[++w].x=b[i]; arr[w].y=i*2+1;
}
for(i=1;i<=k;i++){
scanf("%d",&c[i]);
arr[++w].x=c[i]; arr[w].y=-i;
}
sort(arr+1,arr+w+1);
for(i=1;i<=w;i++)
{
if(arr[i].x!=arr[i-1].x) cnt++;
if(arr[i].y>0){
if(arr[i].y%2==0) a[arr[i].y/2]=cnt;
else b[arr[i].y/2]=cnt;
}
else c[-arr[i].y]=cnt;
}
for(t=1;t<=cnt;t*=2);
for(i=1;i<=k;i++) update(c[i],i);
for(i=1;i<=n;i++){
pos[i].x=query(1,t,1,a[i],b[i]-1); pos[i].y=i;
}
sort(pos+1,pos+n+1); p=k;
for(i=n;i>=1;i--){
for(j=p;j>=pos[i].x+1;j--) update2(c[j]);
p=pos[i].x;
s=query2(t)-query2(b[pos[i].y]-1);
if(pos[i].x){
if(s%2==0) sum+=b2[pos[i].y];
else sum+=a2[pos[i].y];
}
else{
if((sw[pos[i].y]+s)%2==0) sum+=a2[pos[i].y];
else sum+=b2[pos[i].y];
}
}
printf("%lld",sum);
return 0;
}
