#include <bits/stdc++.h> using namespace std; #define pii pair<int, int> const int nx = 1e5+5; int n, m, res; vector<int> c(nx); vector<pii> pic(nx); bool cmp(const pii& a, const pii& b) { if(a.second == b.second) return a.first < b.first; return a.second < b.second; } int main() { cin.tie(NULL)->sync_with_stdio(false); cin >> n >> m; for(int i=0;i<n;i++) cin >> pic[i].first >> pic[i].second; for(int i=0;i<m;i++) cin >> c[i]; sort(pic.begin(), pic.begin() + n, cmp); sort(c.begin(), c.begin() + m); int l = 0, r = 0, prev = 0; while(l < n) { auto [s, v] = pic[l]; // cout << "s : " << s << " v : " << v << '\n'; // cout << "l : " << l << " r : " << r << '\n'; while(r < m && c[r] < s) r++; if(r < m && c[r] >= prev) { // cout << "prev : " << prev << '\n'; // cout << "c[r] : " << c[r] << '\n'; prev = c[r]; r++; res++; } l++; } cout << res ; return 0; }