#include <bits/stdc++.h>
using namespace std;
#define int long long
#define fileio(name) if (fopen(name".inp", "r")) freopen(name".inp", "r", stdin), freopen(name".out", "w", stdout)
const int maxn = 2e5+4, inf = 1e18;
int n, q, a[maxn], b[maxn], t[maxn];
int ac[maxn], bc[maxn], tc[maxn];
int compress(int &x, vector<int> &v) {
return lower_bound(v.begin(), v.end(), x) - v.begin() + 1;
}
int st[maxn*12];
void update(int id, int l, int r, int i, int v) {
if (i < l || i > r) return;
if (l == r) {
st[id] = max(st[id], v);
return;
}
int mid = (l+r)>>1;
update(id*2, l, mid, i, v);
update(id*2+1, mid+1, r, i, v);
st[id] = max(st[id*2], st[id*2+1]);
}
int get(int id, int l, int r, int a, int b) {
if (r < a || b < l) return -inf;
if (a <= l && r <= b) {
return st[id];
}
int mid = (l+r)>>1;
return max(get(id*2, l, mid, a, b), get(id*2+1, mid+1, r, a, b));
}
int bit[maxn*3];
void add(int i, int v) {
while (i <= n*2+q) {
bit[i] += v;
i += (i & (-i));
}
}
int qq(int i) {
int res = 0;
while (i > 0) {
res += bit[i];
i -= (i & (-i));
}
return res;
}
int getr(int l, int r) {
return qq(r) - qq(l-1);
}
struct query {
int idx, x;
bool operator <(const query &A) const {
return x > A.x;
}
} Q[maxn];
int32_t main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
fileio("");
// freopen("debug.txt", "w", stderr);
cin >> n >> q;
vector<int> sech;
for (int i = 1; i <= n; i++) {
cin >> a[i] >> b[i];
sech.push_back(a[i]);
sech.push_back(b[i]);
}
for (int i = 1; i <= q; i++) {
cin >> t[i];
sech.push_back(t[i]);
}
sort(sech.begin(), sech.end());
for (int i = 1; i <= n; i++) {
ac[i] = compress(a[i], sech);
bc[i] = compress(b[i], sech);
}
for (int i = 1; i <= q; i++) {
tc[i] = compress(t[i], sech);
update(1, 1, n*2+q, tc[i], i);
}
for (int i = 1; i <= n; i++) {
Q[i] = {i, get(1, 1, n*2+q, min(ac[i], bc[i]), max(ac[i], bc[i])-1)};
}
sort(Q+1, Q+1+n);
int j = q, res = 0;
for (int i = 1; i <= n; i++) {
while (j > 0 && j > Q[i].x) {
add(tc[j], 1);
j--;
}
int id = Q[i].idx;
if (Q[i].x > 0) {
int p = (1 + getr(max(ac[id], bc[id]), n*2+q)) % 2;
int y[2] = {min(a[id], b[id]), max(a[id], b[id])};
res += y[p];
} else {
int p = getr(max(ac[id], bc[id]), n*2+q) % 2;
int y[2] = {a[id], b[id]};
res += y[p];
}
}
cout << res;
return 0 ^ 0;
}
