#include <cstdio> #include <cstring> #include <vector> #include <algorithm> #include <utility> using namespace std; typedef pair<int,int> pi; vector<int> v; int n,k; int a[200005], b[200005], q[200005]; bool flip[200005]; struct rmq{ int tree[1050000], lim; void init(int n){ for(lim = 1; lim <= n; lim <<= 1); memset(tree,-1,sizeof(tree)); } void add(int x, int v){ x += lim; tree[x] = v; while(x>1){ x >>= 1; tree[x] = max(tree[2*x],tree[2*x+1]); } } int q(int s, int e){ s += lim; e += lim; int r = -1; while(s < e){ if(s%2 == 1) r = max(r,tree[s++]); if(e%2 == 0) r = max(r,tree[e--]); s >>= 1; e >>= 1; } if(s == e) r = max(r,tree[s]); return r; } }rmq; struct bit{ int tree[530000], lim; void init(int n){ lim = n+1; // for(lim = 1; lim <= n+1; lim <<= 1); } void add(int x){ x++; while(x <= lim){ tree[x]++; x += x & -x; } } int sum(int x){ x++; int r = 0; while(x){ r += tree[x]; x -= x & -x; } return r; } }bit; void input(){ scanf("%d %d",&n,&k); for (int i=0; i<n; i++) { scanf("%d %d",&a[i],&b[i]); if(a[i] > b[i]){ swap(a[i],b[i]); flip[i] = 1; } v.push_back(a[i]); v.push_back(b[i]); } sort(v.begin(),v.end()); v.resize(unique(v.begin(),v.end()) - v.begin()); for (int i=0; i<n; i++) { a[i] = (int)(lower_bound(v.begin(),v.end(),a[i]) - v.begin()); b[i] = (int)(lower_bound(v.begin(),v.end(),b[i]) - v.begin()); } for (int i=0; i<k; i++) { scanf("%d",&q[i]); q[i] = (int)(upper_bound(v.begin(),v.end(),q[i]) - v.begin()) - 1; } } int table[200005]; int main(){ input(); rmq.init((int)v.size()); for (int i=0; i<k; i++) { rmq.add(q[i],i); } for (int i=0; i<n; i++) { table[i] = rmq.q(a[i],b[i]-1); } bit.init((int)v.size()); for (int i=0; i<k; i++) { bit.add(q[i]); } for (int i=0; i<n; i++) { if(table[i] >= 0) flip[i] = 1; } for (int i=0; i<k; i++) { for (int j=0; j<n; j++) { if(table[j] < i && b[j] <= q[i]){ flip[j] ^= 1; } } } long long ret = 0; for (int i=0; i<n; i++) { if(flip[i]) ret += v[b[i]]; else ret += v[a[i]]; } printf("%lld",ret); }