#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int n,x,y;
    cin>>n>>x>>y;
    int arr[n][4];
    int sum=0;
    for(int i=0;i<n;i++)
        {
            cin>>arr[i][0]>>arr[i][1]>>arr[i][2]>>arr[i][3];
    }
    int tsum=0;
    for(int i=0;i<n;i++)
        {
            
            tsum+=arr[i][3];
    }
    sum=max(sum,tsum);
    cout<<sum;
    
    return 0;
}