#include <stdio.h>
#include <fstream>
#include <iostream>
#include <vector>

using namespace std;


int main() {

    struct lamp {
        int distance = 0;
        int height = 0;
        int count = 0;
    };
    int N = 0;
    int result = 0;
    vector<int> road(100);
    vector<lamp> array(100);

    ifstream input("input.txt");
    ofstream output("output.txt");

    input >> N;

    if (N >= 1) {
        for (int i = 0; i < N; i++) {
            input >> array[i].distance;
            input >> array[i].height;
            int l = (array[i].distance - array[i].height);
            int r = (array[i].distance + array[i].height);
            if (l < 0)
                l = 0;
            if (r > 99)
                r = 99;
            for (int j = l; j < r; j++) {
                road[j]++;
            }
        }

        for (int i = 0; i < 100; i++) {
            if (result < road[i]) {
                result = road[i];
            }
        }

        output << result;
    }
    return 0;
}