#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define FOR(i, a, b) for (int i = a, _b = b; i <= _b; ++i)
#define FORD(i, a, b) for (int i = a, _b = b; i >= _b; --i)
#define FORLL(i, a, b) for (ll i = a, _b = b; i <= _b; ++i)
#define FORDLL(i, a, b) for (ll i = a, _b = b; i >= _b; --i)
#define all(x) x.begin(), x.end()
#define uni(x) sort(all(x)), x.erase(unique(all(x)), x.end())
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
#define dbg(...) debug(#__VA_ARGS__, __VA_ARGS__)
template<typename T>
void __print_one(const char *&s, const T &x)
{
while (*s == ' ') ++s;
const char *p = s;
int bal = 0;
while (*s)
{
if (*s == '(') ++bal;
else if (*s == ')') --bal;
else if (*s == ',' && bal == 0) break;
++s;
}
cerr.write(p, s - p) << " = " << x;
if (*s == ',')
{
++s;
cerr << " , ";
}
}
template<typename... Args>
void debug(const char *s, Args... args)
{
cerr << "[ ";
int dummy[] = { 0 , ( __print_one(s, args) , 0 )... };
(void)dummy;
cerr << " ]\n\n";
}
template<class X>
bool maximize(X &a, X b)
{
if (a < b)
{
a = b;
return true;
}
return false;
}
template<class X>
bool minimize(X &a, X b)
{
if (a > b)
{
a = b;
return true;
}
return false;
}
// --------------------------------------------------------------------------------------------
const int maxn = 2e5 + 3;
int n, q, a[maxn][2];
// --------------------------------------------------------------------------------------------
namespace sub1
{
int ans[maxn];
void solve()
{
while (q--)
{
int x; cin >> x;
FOR(i, 1, n)
if (a[i][ans[i]] <= x)
ans[i] ^= 1;
}
ll res = 0;
FOR(i, 1, n)
res += a[i][ans[i]];
cout << res;
}
}
namespace AC
{
int T[maxn], state[maxn], Ma[maxn][20], lg[maxn];
vector<int> ids;
struct FenTree
{
vector<int> fw;
void init(int n)
{
fw.assign(n + 3, 0);
}
void upd(int pos, int val)
{
for (; pos; pos &= pos - 1)
fw[pos] ^= val;
}
int get(int pos)
{
int res = 0;
for (; pos < int(fw.size()); pos += pos & -pos)
res ^= fw[pos];
return res;
}
};
int lower(int x) {return lower_bound(all(ids), x) - ids.begin() + 1;}
int upper(int x) {return upper_bound(all(ids), x) - ids.begin() + 1;}
int get_max(int l, int r)
{
l = max(l, 1);
r = min(r, int(ids.size()));
if (l > r) return 0;
int k = lg[r - l + 1];
return max(Ma[l][k], Ma[r - (1 << k) + 1][k]);
}
void solve()
{
FOR(i, 1, n)
{
if (a[i][0] > a[i][1])
{
state[i] = 1;
swap(a[i][0], a[i][1]);
}
}
FOR(iq, 1, q)
cin >> T[iq];
vector<int> sortT(q);
iota(all(sortT), 1);
sort(all(sortT), [&](const int &x, const int &y) {
return T[x] > T[y];
});
vector<int> sortA(n);
iota(all(sortA), 1);
sort(all(sortA), [&](const int &x, const int &y) {
return a[x][1] > a[y][1];
});
FOR(i, 1, q)
{
ids.push_back(T[i]);
}
uni(ids);
FOR(iq, 1, q)
{
int id = lower(T[iq]);
maximize(Ma[id][0], iq);
}
FOR(j, 1, 19)
FOR(i, 1, int(ids.size()) - (1 << j) + 1)
Ma[i][j] = max(Ma[i][j - 1], Ma[i + (1 << j - 1)][j - 1]);
FOR(i, 2, q)
lg[i] = lg[i >> 1] + 1;
FenTree fw;
fw.init(q);
ll res = 0;
int j = 0;
for (int iA : sortA)
{
while (j < int(sortT.size()) && T[sortT[j]] >= a[iA][1])
{
fw.upd(sortT[j], 1);
++j;
}
int l = lower(a[iA][0]), r = lower(a[iA][1]) - 1;
int pos = get_max(l, r);
if (pos == 0)
{
res += a[iA][fw.get(1) ^ state[iA]];
}
else
{
res += a[iA][fw.get(pos) ^ 1];
}
}
cout << res;
}
}
void solve()
{
cin >> n >> q;
FOR(i, 1, n)
cin >> a[i][0] >> a[i][1];
AC :: solve();
}
signed main()
{
ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define TASK "TEST"
if (fopen(TASK".INP", "r"))
{
freopen(TASK".INP", "r", stdin);
freopen(TASK".OUT", "w", stdout);
}
solve();
return 0;
}
