#include <bits/stdc++.h>
#define pii pair<int, int>
#define x first
#define y second
using namespace std;
const int N = 2e5 + 10;
int n, k, que[N];
long long ans;
int seg[4*N], fen[N];
vector<int> coord;
vector<pii> quer, card;
void update( int pos, int val, int l = 1, int r = k, int idx = 1 ) {
//printf("l %d r %d\n",l,r);
if( l == r ) return void( seg[idx] = val );
int mid = l + r >> 1;
if( pos <= mid ) update( pos, val, l, mid, idx<<1 );
else update( pos, val, mid+1, r, idx<<1|1 );
seg[idx] = max( seg[idx<<1], seg[idx<<1|1] );
}
int query( int ll, int rr, int l = 1, int r = k, int idx = 1 ) {
if( ll > rr ) return 0;
if( l > rr || r < ll ) return 0;
if( l >= ll && r <= rr ) return seg[idx];
int mid = l + r >> 1;
return max( query( ll, rr, l, mid, idx<<1 ), query( ll, rr, mid+1, r, idx<<1|1 ) );
}
void fup( int idx ) { for( int i = idx ; i < N ; i+= i & -i ) fen[i] += 1; }
int fque( int idx ) {
int ret = 0;
for( int i = idx ; i > 0 ; i -= i & -i ) ret += fen[i];
return ret;
}
int main()
{
scanf("%d %d",&n,&k);
for( int i = 1, a, b ; i <= n ; i++ ) {
scanf("%d %d",&a,&b);
card.emplace_back( a, b );
}
for( int i = 1, a ; i <= k ; i++ ) {
scanf("%d",&que[i]);
coord.emplace_back( que[i] );
}
sort( coord.begin(), coord.end() );
for( int i = 1 ; i <= k ; i++ ) {
que[i] = lower_bound( coord.begin(), coord.end(), que[i] ) - coord.begin() + 1;
//printf("%d %d\n",i,que[i]);
update( que[i], i );
}
//printf("%d\n",query( 1, k ) );
for( int i = 0 ; i < card.size() ; i++ ) {
int a = min( card[i].x, card[i].y ), b = max( card[i].x, card[i].y );
a = lower_bound( coord.begin(), coord.end(), a ) - coord.begin() + 1;
b = upper_bound( coord.begin(), coord.end(), b-1 ) - coord.begin();
int qq = query( a, b );
//printf("%d %d %d %d\n",i,a,b,qq);
if( qq )
if( card[i].x < card[i].y ) swap( card[i].x, card[i].y );
quer.emplace_back( qq, i );
}
sort( quer.begin(), quer.end(), greater<pii>() );
int ptr = k;
for( pii i : quer ) {
//printf("%d %d\n",i.x,i.y);
while( ptr > 0 && ptr > i.x ) {
//printf("idx ptr%d %d\n",que[ptr],ptr);
fup( que[ptr] );
ptr--;
}
int b = max( card[i.y].x, card[i.y].y );
int idx = lower_bound( coord.begin(), coord.end(), b ) - coord.begin();
int cnt = fque( N-1 ) - fque( idx );
//printf("%d\n",fque(N-1));
//printf("idx%d cnt%d\n",idx,cnt);
if( cnt % 2 ) swap( card[i.y].x, card[i.y].y );
ans += ( long long )card[i.y].x;
//printf("%d %d\n",i.y,card[i.y].x);
}
printf("%lld",ans);
return 0;
}
