#include <bits/stdc++.h>
#define DIM 200010
using namespace std;
struct card{
int x,y,poz;
} v[DIM];
int aint[DIM*4],aib[DIM*4],poz[DIM],sol[DIM],w[DIM*4];
vector <int> events[DIM];
pair <int,int> t[DIM];
int n,i,j,k,el;
int cautare_binara (int v[], int n, int val){
int st = 1, dr = n;
while (st <= dr){
int mid = (st+dr)>>1;
if (v[mid] == val)
return mid;
if (v[mid] < val)
st = mid+1;
else dr = mid-1;
}
}
void build (int nod, int st, int dr){
if (st == dr){
aint[nod] = t[st].second;
return;
}
int mid = (st+dr)>>1;
build (nod<<1,st,mid);
build ((nod<<1)|1,mid+1,dr);
aint[nod] = max (aint[nod<<1],aint[(nod<<1)|1]);
}
int query (int nod, int st, int dr, int x, int y){
if (x <= st && dr <= y)
return aint[nod];
int mid = (st+dr)>>1, sol_st = 0, sol_dr = 0;
if (x <= mid)
sol_st = query (nod<<1,st,mid,x,y);
if (y > mid)
sol_dr = query ((nod<<1)|1,mid+1,dr,x,y);
return max (sol_st,sol_dr);
}
inline int cmp (pair <int,int> a, pair <int,int> b){
return a.second < b.second;
}
inline int cmp2 (card a, card b){
return max(a.x,a.y) < max(b.x,b.y);
}
inline int cmp3 (pair <int,int> a, pair <int,int> b){
return a.first > b.first;
}
inline int cmp4 (card a, card b){
return a.poz < b.poz;
}
void update_aib (int p, int val){
for (;p<=el;p+=(p&-p))
aib[p] += val;
}
int query_aib (int p){
int sol = 0;
for (;p;p-=(p&-p))
sol += aib[p];
return sol;
}
int main (){
//ifstream cin ("date.in");
//ofstream cout ("date.out");
cin>>n>>k;
for (i=1;i<=n;i++){
cin>>v[i].x>>v[i].y;
v[i].poz = i;
w[++el] = v[i].x;
w[++el] = v[i].y;
}
for (i=1;i<=k;i++){
cin>>t[i].first;
t[i].second = i;
w[++el] = t[i].first;
}
sort (w+1,w+el+1);
int el2 = 1;
for (i=2;i<=el;i++)
if (w[i] != w[i-1])
w[++el2] = w[i];
el = el2;
sort (t+1,t+k+1);
build (1,1,k);
for (i=1;i<=n;i++){
int st = 1, dr = k, sol_x = 0, sol_y = 0;
while (st <= dr){
int mid = (st+dr)>>1;
if (t[mid].first >= min(v[i].x,v[i].y) ){
sol_x = mid;
dr = mid-1;
} else st = mid+1;
}
st = 1, dr = k;
while (st <= dr){
int mid = (st+dr)>>1;
if (t[mid].first < max(v[i].x,v[i].y)){
sol_y = mid;
st = mid+1;
} else dr = mid-1;
}
if (sol_x && sol_y){
poz[i] = query (1,1,k,sol_x,sol_y);
events[poz[i]].push_back(i);
}
//cout<<poz[i]<<"\n";
}
sort (t+1,t+k+1,cmp);
for (i=k;i>=0;i--){
for (auto it : events[i]){
int val_y = cautare_binara(w,el,max(v[it].x,v[it].y));
sol[it] = query_aib(el) - query_aib(val_y - 1);
}
if (i){
int val_t = cautare_binara(w,el,t[i].first);
update_aib (val_t,1);
}
}
long long ans = 0;
for (i=1;i<=n;i++){
if (!poz[i]){
if (sol[i] % 2)
ans += v[i].y;
else ans += v[i].x;
} else {
if (sol[i] % 2 == 0)
ans += max(v[i].x,v[i].y);
else ans += min(v[i].x,v[i].y);
}
}
cout<<ans;
return 0;
}
