#include <bits/stdc++.h> #define fi first #define se second #define mp make_pair #define pb push_back #define eb emplace_back #define ar array using namespace std; typedef long long ll; typedef pair<int, int> ii; signed main(void) { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); #ifdef LOCAL freopen("A.INP", "r", stdin); freopen("A.OUT", "w", stdout); #endif // LOCAL int n, m; cin >> n >> m; vector<ii> pictures(n); vector<int> frames(m); for (auto & it : pictures) { cin >> it.se >> it.fi; } for (auto & it : frames) { cin >> it; } sort(pictures.begin(), pictures.end()); sort(frames.begin(), frames.end()); int cur = n - 1, res = 0; for (int i = m - 1; i >= 0; --i) { while (pictures[cur].se > frames[i]) { --cur; } if (cur >= 0) { ++res; --cur; } } cout << res; }