#include <bits/stdc++.h> #define _NVQ "" #define int long long #define pii pair<int,int> #define fi first #define se second using namespace std; int n,m,c[100005]; pii sv[100005]; int32_t main() { // if(fopen(_NVQ".INP","r")) // { // freopen(_NVQ".INP","r",stdin); // freopen(_NVQ".OUT","w",stdout); // } ios_base::sync_with_stdio(0); cin.tie(0);cout.tie(0); cin >> n >> m; for (int i=1;i<=n;++i) { cin >> sv[i].fi >> sv[i].se; } for (int i=1;i<=m;++i) { cin >> c[i]; } sort(c+1,c+m+1); sort(sv+1,sv+n+1); int id=1; priority_queue <int,vector<int>,greater<int>> pq; vector <int> v; for (int i=1;i<=m;++i) { while (sv[id].fi <= c[i] && id <= n) { pq.push(sv[id].se); ++id; } if (pq.empty()) continue; int x = pq.top(); pq.pop(); auto beo = upper_bound(v.begin(),v.end(),x); if (beo==v.end()) v.push_back(x); else *beo = x; } cout << v.size(); }