//  {{{

#include <bits/stdc++.h>
using namespace std;

#ifndef ONLINE_JUDGE
#include "debug.cpp"
#else
#define debug(...)
#define debugArr(...)
#endif

using ll = long long;

const int inf = 1073741823;
const ll infl = 1LL << 60;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define rep(i, b) for (auto i = 0; i < (b); i++)
#define reps(i, b) for (auto i = 1; i <= (b); i++)

// }}}


const int mxN = 500001;
int n,ans,curx,cure;
bool visited[mxN];
//bool influ[500001][500001];

struct node{
    int x,e;
}re[mxN];

bool cmp(const node a, const node b){
    return a.e > b.e;
}

int main() {
    scanf("%d",&n);
    bool subtask1=1;
    memset(visited,0,sizeof(visited));
    for(int i=1; i<=n; i++){
        scanf("%d%d",&re[i].x,&re[i].e);
        if(i>1 && re[i].e != re[i-1].e)subtask1=0;
    }
    if(subtask1){
        set<int> ss;
        for(int i=1; i<=n; i++){
            ss.insert(re[i].x);
        }
        printf("%d",(int)ss.size());
        return 0;
    }
    sort(re+1, re+n+1, cmp);

    bool allclear=0;
    for(int i=1; i<=n; i++){
        allclear=1;
        curx = re[i].x;
        cure = re[i].e;
        visited[i] = 1;
        for(int j=1; j<=n; j++){
            if(cure - re[j].e >= abs(curx - re[j].x))visited[j] = 1;
            if(!visited[j])allclear=0;
        }
        if(allclear){ans=i; break;}
    }
    printf("%d",ans);
}



// subtask 1, since all e is equal, just count the number of unique coordinates