#pragma GCC target ("avx")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
//#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#define _USE_MATH_DEFINES
#include<iostream>
#include<string>
#include<queue>
#include<cmath>
#include<map>
#include<set>
#include<list>
#include<iomanip>
#include<vector>
#include<random>
#include<functional>
#include<algorithm>
#include<stack>
#include<cstdio>
#include<cstring>
#include<bitset>
#include<unordered_map>
#include<climits>
#include<fstream>
#include<complex>
#include<time.h>
#include<cassert>
#include<functional>
#include<numeric>
#include<tuple>
using namespace std;
using ll = long long;
using ld = long double;
using H = pair<ll, ll>;
using P = pair<ll, H>;
using vi = vector<ll>;
#define all(a) (a).begin(),(a).end()
#define fs first
#define sc second
#define xx first
#define yy second.first
#define zz second.second
#define Q(i,j,k) mkp(i,mkp(j,k))
#define rng(i,s,n) for(ll i = (s) ; i < (n) ; i++)
#define rep(i,n) rng(i, 0, (n))
#define mkp make_pair
#define vec vector
#define pb emplace_back
#define siz(a) (int)(a).size()
#define crdcomp(b) sort(all((b)));(b).erase(unique(all((b))),(b).end())
#define getidx(b,i) (lower_bound(all(b),(i))-(b).begin())
#define ssp(i,n) (i==(ll)(n)-1?"\n":" ")
#define ctoi(c) (int)(c-'0')
#define itoc(c) (char)(c+'0')
#define cyes printf("Yes\n")
#define cno printf("No\n")
#define cdf(n) for(int quetimes_=(n);quetimes_>0;quetimes_--)
#define gcj printf("Case #%lld: ",qq123_+1)
#define readv(a,n) a.resize(n,0);rep(i,(n)) a[i]=read()
#define found(a,x) (a.root(x)!=a.end())
constexpr ll mod = (ll)1e9 + 7;
constexpr ll Mod = 998244353;
constexpr ld EPS = 1e-10;
constexpr ll inf = (ll)3 * 1e18;
constexpr int Inf = (ll)15 * 1e8;
constexpr int dx[] = { -1,1,0,0 }, dy[] = { 0,0,-1,1 };
template<class T>bool chmax(T& a, const T& b) { if (a < b) { a = b; return 1; } return 0; }
template<class T>bool chmin(T& a, const T& b) { if (b < a) { a = b; return 1; } return 0; }
ll read() { ll u, k = scanf("%lld", &u); return u; }
string reads() { string s; cin >> s; return s; }
H readh(short g = 0) { H u; int k = scanf("%lld %lld", &u.fs, &u.sc); if (g == 1) u.fs--, u.sc--; if (g == 2) u.fs--; return u; }
bool ina(H t, int h, int w) { return 0 <= t.fs && t.fs < h && 0 <= t.sc && t.sc < w; }
bool ina(int t, int l, int r) { return l <= t && t < r; }
ll gcd(ll i, ll j) { return j ? gcd(j, i % j) : i; }
ll ppc(ll x) {
int sum = 0; for (int i = 0; i < 60; i++)if ((1ll << i) & x) sum++;
return sum;
}
void fin1() { printf("-1\n"); exit(0); }
void fin0() { printf("0\n"); exit(0); }
template<typename T>
class csum {
vec<T> v;
public:
csum(vec<T>& a) :v(a) { build(); }
csum() {}
csum(int sz) { init(sz); }
void init(int sz) { v = vector<T>(sz, 0); }
void init(vec<T>& a) { v = a; build(); }
void build() {
for (int i = 1; i < v.size(); i++) v[i] += v[i - 1];
}
void add(int l, int r, T x) {
v[l] += x;
v[r] -= x;
}//[l,r)
//[l,r]
T a(int l, int r) {
if (r < l) return 0;
return v[r] - (l == 0 ? 0 : v[l - 1]);
}
//[l,r)
T b(int l, int r) {
return a(l, r - 1);
}
T a(pair<int, int>t) {
return a(t.first, t.second);
}
T b(pair<int, int>t) {
return b(t.first, t.second);
}
T operator[](int x)const {
return v[x];
}
};
template<ll mod>
class modint {
public:ll v;
modint(ll v = 0) { s(v % mod + mod); }
constexpr static int fn_ = (ll)2e6 + 5;
static vector<modint>fact, comp;
modint pow(ll x) const {
modint b(v), c(1);
while (x) {
if (x & 1) c *= b;
b *= b;
x >>= 1;
}
return c;
}
inline modint& s(int vv) {
v = vv < mod ? vv : vv - mod;
return *this;
}
inline modint inv()const { return pow(mod - 2); }
inline modint operator-()const { return modint() - *this; }
inline modint& operator+=(const modint b) { return s(v + b.v); }
inline modint& operator-=(const modint b) { return s(v + mod - b.v); }
inline modint& operator*=(const modint b) { v = v * b.v % mod; return *this; }
inline modint& operator/=(const modint b) { v = v * b.inv().v % mod; return *this; }
inline modint operator+(const modint& b) const { return modint(v) += b; }
inline modint operator-(const modint& b) const { return modint(v) -= b; }
inline modint operator*(const modint& b) const { return modint(v) *= b; }
inline modint operator/(const modint& b) const { return modint(v) /= b; }
friend ostream& operator<<(ostream& os, const modint& m) {
return os << m.v;
}
friend istream& operator>>(istream& is, modint& m) {
int x; is >> x; m = modint(x);
return is;
}
bool operator<(const modint& r)const { return v < r.v; }
bool operator>(const modint& r)const { return v > r.v; }
bool operator<=(const modint& r)const { return v <= r.v; }
bool operator>=(const modint& r)const { return v >= r.v; }
bool operator==(const modint& r)const { return v == r.v; }
bool operator!=(const modint& r)const { return v != r.v; }
explicit operator bool()const { return v; }
explicit operator int()const { return v; }
modint comb(modint k) {
if (k > *this) return modint();
if (fact.empty()) combinit();
if (v >= fn_) {
if (k > *this - k) k = *this - k;
modint tmp(1);
for (int i = v; i >= v - k.v + 1; i--) tmp *= modint(i);
return tmp * comp[k.v];
}
return fact[v] * comp[k.v] * comp[v - k.v];
}//nCk
modint perm(modint k) {
if (k > *this) return modint();
if (fact.empty()) combinit();
if (v >= fn_) {
modint tmp(1);
for (int i = v; i >= v - k.v + 1; i--) tmp *= modint(i);
return tmp;
}
return fact[v] * comp[v - k.v];
}//nPk
static void combinit() {
fact.assign(fn_, modint());
fact[0] = 1;
for (int i = 1; i < fn_; i++) fact[i] = fact[i - 1] * modint(i);
comp.assign(fn_, modint());
comp[fn_ - 1] = fact[fn_ - 1].inv();
for (int i = fn_ - 2; i >= 0; i--) comp[i] = comp[i + 1] * modint(i + 1);
}
};
using mint = modint<ll(1e9 + 7)>; template<>vec<mint> mint::fact = vec<mint>(); template<>vec<mint> mint::comp = vec<mint>();
//--------------------------------------------------------------
//--------------------------------------------------------------
int n, m, rr = 1;
vi dat[800000];
//a以上b未満の値が初めて出てくるindexを返す 出てこないならm
int lb(int i, int a, int b, int l, int r) {
if (lower_bound(all(dat[i]), b) - lower_bound(all(dat[i]), a) == 0) {
return m;
}
if (r - l == 1) return l;
int k = lb(i * 2, a, b, l, (l + r) / 2);
if (k < m) return k;
return lb(i * 2 + 1, a, b, (l + r) / 2, r);
}
int query(int i, int a, int b, int x, int l, int r) {
if (b <= l || r <= a) return 0;
if (a <= l && r <= b) {
return siz(dat[i]) - (lower_bound(all(dat[i]), x) - dat[i].begin());
}
return query(i * 2, a, b, x, l, (l + r) / 2) + query(i * 2 + 1, a, b, x, (l + r) / 2, r);
}//a以上b未満の区間に、x以上の値は何個あるか？
signed main() {
cin >> n >> m;
vec<H>a; vi b;
rep(i, n) a.pb(readh());
readv(b, m);
reverse(all(b));
while (rr < m) rr *= 2;
rng(i, rr, rr + m) dat[i].pb(b[i - rr]);
for (int i = rr - 1; i >= 1; i--) {
merge(all(dat[i * 2]), all(dat[i * 2 + 1]), back_inserter(dat[i]));
}
ll ans = 0;
rep(i, n) {
int k = lb(1, min(a[i].fs, a[i].sc), max(a[i].fs, a[i].sc), 0, rr);
int num = query(1, 0, k, max(a[i].fs, a[i].sc), 0, rr);
if (k == m) {
if (num % 2 == 0) ans += a[i].fs;
else ans += a[i].sc;
}
else {
if (a[i].fs > a[i].sc) swap(a[i].fs, a[i].sc);
//a[i].fsがひっくり返されたのがk
//現在の表はa[i].sc
if (num % 2 == 0) ans += a[i].sc;
else ans += a[i].fs;
}
}
cout << ans << endl;
}
