#include<bits/stdc++.h>
using namespace std;
#define task "a"
#define se second
#define fi first
#define ll long long
#define ii pair<ll, ll>
const long mxN = 2e5 + 7;
int n, a[mxN][3], tree[mxN * 4], q;
bool cnt[mxN * 4], ans[mxN];
vector<ii> val, querry[mxN];
void Build(int j = 1, int l = 0, int r = q)
{
if (l == r)
{
tree[j] = val[l].se;
return;
}
int mid = (l + r) / 2;
Build(j * 2, l, mid);
Build(j * 2 + 1, mid + 1, r);
tree[j] = max(tree[j * 2], tree[j * 2 + 1]);
}
int Get(int u, int v, int j = 1, int l = 0, int r = q)
{
if (u > val[r].fi || val[l].fi > v)
return -1;
if (u <= val[l].fi && val[r].fi <= v)
return tree[j];
int mid = (l + r) / 2;
return max(Get(u, v, j * 2, l, mid), Get(u, v, j * 2 + 1, mid + 1, r));
}
void Upd(int vt, int j = 1, int l = 0, int r = q)
{
if (l > vt || vt > r)
return;
cnt[j] ^= 1;
if (l == r)
return;
int mid = (l + r) / 2;
Upd(vt, j * 2, l, mid);
Upd(vt, j * 2 + 1, mid + 1, r);
}
bool Get_cnt(int vt, int j = 1, int l = 0, int r = q)
{
if (r < vt)
return 0;
if (vt <= l)
return cnt[j];
int mid = (l + r) / 2;
return Get_cnt(vt, j * 2, l, mid) ^ Get_cnt(vt, j * 2 + 1, mid + 1, r);
}
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
//freopen(task".INP", "r", stdin);
//freopen(task".OUT", "w", stdout);
cin >> n >> q;
for (int i = 1; i <= n; i++)
{
cin >> a[i][0] >> a[i][1];
if (a[i][0] > a[i][1])
{
swap(a[i][0], a[i][1]);
ans[i] = 1;
}
}
q--;
for (int i = 0; i <= q; i++)
{
int tmp;
cin >> tmp;
val.push_back({tmp, i});
}
sort(val.begin(), val.end());
Build();
for (int i = 1; i <= n; i++)
{
int tmp = Get(a[i][0], a[i][1] - 1);
if (tmp > 0)
ans[i] = 1;
querry[lower_bound(val.begin(), val.end(), ii(a[i][1], 0)) - val.begin()].push_back({i, tmp});
}
for (int i = q; i >= 0; i--)
{
Upd(val[i].se);
for (ii j : querry[i])
ans[j.fi] ^= Get_cnt(j.se);
}
ll sum = 0;
for (int i = 1; i <= n; i++)
sum += a[i][ans[i]];
cout << sum;
}
