C++ :

#include <iostream>
#include <bits/stdc++.h>
using namespace std;
#define int long long 
 
const int maxn=2510;
pair<int,int>cows[maxn];
int n,m;
signed main(){
    cin>>n>>m;
    for(int i=0;i<n;i++)cin>>cows[i].first>>cows[i].second;
    sort(cows,cows+n);
    
    
    map<int,int>spfs;
    for(int i=0;i<m;i++){
        int spf,cover;
        cin>>spf>>cover;
        spfs[spf]+=cover;
    }
    
    int res=0;
    
    //spfs[0]=spfs[1001]=n;
 
    for(int i=n-1;i>=0;i--){
        
        auto cow=cows[i];
        auto it=spfs.upper_bound(cow.second);
        it--;
        if(it->first>=cow.first && it->first<=cow.second){
            res++;
            if(--it->second==0)spfs.erase(it);
        }
    }
    
    cout<<res<<endl;
}

#include <iostream> #include <bits/stdc++.h> using namespace std; #define int long long

const int maxn=2510; pair<int,int>cows[maxn]; int n,m; signed main(){ cin>>n>>m; for(int i=0;i<n;i++)cin>>cows[i].first>>cows[i].second; sort(cows,cows+n);

map<int,int>spfs;
for(int i=0;i<m;i++){
    int spf,cover;
    cin>>spf>>cover;
    spfs[spf]+=cover;
}

int res=0;

//spfs[0]=spfs[1001]=n;

for(int i=n-1;i>=0;i--){
    
    auto cow=cows[i];
    auto it=spfs.upper_bound(cow.second);
    it--;
    if(it->first>=cow.first && it->first<=cow.second){
        res++;
        if(--it->second==0)spfs.erase(it);
    }
}

cout<<res<<endl;

}

#include<bits/stdc++.h>
 using namespace std;
const int MAXN=5000;
struct cow{
   int minSPF,maxSPF;
}c[MAXN];
int SPF[MAXN],cover[MAXN];
int L,C;
int J=0;
bool myc(cow a,cow b) { return a.minSPF>b.minSPF; }
int main()
{
   cin>>C>>L;
   for(int i=1;i<=C;i++) scanf("%d %d",&c[i].minSPF,&c[i].maxSPF);
   sort(c+1,c+C+1,myc);
   for(int i=1;i<=L;i++) scanf("%d %d",&SPF[i],&cover[i]);
   for(int i=1;i<=C;i++)
   {
   	int x=c[i].minSPF,y=c[i].maxSPF;
   	int use=-1,num;
	for(int j=1;j<=L;j++)
   	 if(SPF[j]>=x && SPF[j]<=y && cover[j] && SPF[j]>use )  use=SPF[j],num=j;	
   	if(use!=-1) { J++; cover[num]--;} 
   }
   cout<<J;
} 

#include<bits/stdc++.h> #include<cstdio> #include<math.h> #include<queue> #include<string.h> #include<vector> #include<stdio.h> #include<stack> #include<iostream> #include<iomanip> using namespace std; const int MAXN=5000; struct cow{ int minSPF,maxSPF; }c[MAXN]; int SPF[MAXN],cover[MAXN]; int L,C; int J=0; bool myc(cow a,cow b) { return a.minSPF>b.minSPF; } int main() { cin>>C>>L; for(int i=1;i<=C;i++) scanf("%d %d",&c[i].minSPF,&c[i].maxSPF); sort(c+1,c+C+1,myc); for(int i=1;i<=L;i++) scanf("%d %d",&SPF[i],&cover[i]); for(int i=1;i<=C;i++) { int x=c[i].minSPF,y=c[i].maxSPF; int use=-1,num; for(int j=1;j<=L;j++) if(SPF[j]>=x && SPF[j]<=y && cover[j] && SPF[j]>use ) use=SPF[j],num=j; if(use!=-1) { J++; cover[num]--;} } cout<<J; }

#define pii pair<int,int>
#define fi first
#define  se second
using namespace std;
const int N = 1e3 + 10;
vector<pii > cow;
int cover[N], c, l;
set<int> spf;

int main() {
    cin >> c >> l;
    for (int i = 1; i <= c; i++) {
        int x, y;
        scanf("%d%d", &x, &y);
        cow.push_back({x, y});
    }
    sort(cow.begin(), cow.end());
    reverse(cow.begin(), cow.end());
    for (int i = 1; i <= l; i++) {
        int x, y;
        scanf("%d%d", &x, &y);
        if (!cover[x])
            spf.insert(-x);
        cover[x] += y;
    }
    int ans = 0;
    for (auto &it:cow) {
        int x = -(*spf.lower_bound(-it.se));
        if (x < it.fi)continue;
        ans++;
        if (!(--cover[x]))spf.erase(-x);
    }
    cout << ans;
    return 0;
}