防晒

 

#include <bits/stdc++.h>
using namespace std;
const int N = 2510;
typedef pair<int, int> PII;
PII a[N]; //牛的min和max
int main() {
    int c, l;
    cin >> c >> l;
    for (int i = 0; i < c; i++) {
        cin >> a[i].first >> a[i].second;
    }
    sort(a, a + c);
    map<int, int> spf; 
    //first是点的下标，second是数量
    for (int i = 0; i < l; i++) {
        int sp, cover;
        cin >> sp >> cover;
        spf[sp] += cover;
    }
    int res = 0;
    spf[0] = spf[1001] = c; //哨兵
    for (int i = c - 1; i >= 0; i--) {
        map<int, int>::iterator t = spf.upper_bound(a[i].second);
        t--;
        if (t -> first >= a[i].first && t -> first <= a[i].second) {
            res++;
            t -> second--;
            if (t -> second == 0) {
                spf.erase(t);
            }
            
        }
    }
    cout << res << endl;
    return 0;
}