#include<bits/stdc++.h>
#define rip(i,a,b) for(int i = a;i<b;i++)
using namespace std;
void printV(vector<pair<int,int>> v){
    rip(i,0,v.size())cout << v[i].first<< " " << v[i].second<<endl;
    cout << endl;
}
int maxPoints(vector<string> points){
    stringstream s;
    vector<pair<int,int>>v;
    s << points[0];
    int n;s>>n;
    int x,y;
    for(int i = 1;i<n+1;i++){
        stringstream ss;
        ss << points[i];
        ss >> x >> y;
        v.push_back({y,x});
    }
    sort(v.begin(),v.end());
    int res = -1;
    set<int> m;
    m.insert(v[0].second);
    for(int i = 1;i<v.size();i++){
        if(v[i].first == v[i-1].first){
            //cout <<v[i].second<< " got here"<<endl;

            m.insert(v[i].second);
        }else{
            //cout << "LOL: " << m.count(0)<<endl;
            int c = 0;
            if(m.count(v[i].second))c++;

            for(int j = i+1;j<v.size();j++){
                if(v[j].first != v[j-1].first){
                    res = max(res,c);
                    c = 0;
                }
                //if(m[v[j].second])c++;
                if(m.count(v[j].second))c++;
            }
            res = max(res,c);
            m.clear();
        }
        m.insert(v[i].second);
    }
    return res;
}
int main(){
    int n;
    //cin >> n;
    cout << maxPoints({"20","24331 11582","40676 17095","36278 30532","41086 28684","20917 27058","12962 30532","12962 27058","12686 41706","11904 36954","36278 27058","20917 30532","28688 28593","37112 27058","18069 27058","32436 27058","37390 21596","18069 30532","27549 28756","32436 30532","37112 30532"});

}