#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
//mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
//ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
const int tree_siz = 1024*1024-1;
struct segtree
{
pll drzewo[tree_siz+1];
segtree()
{
rep2(i,1,tree_siz) drzewo[i] = {1e18,-1};
}
pll get_min(int akt, int p1, int p2, int s1, int s2)
{
if(p2 < s1 || p1 > s2) return {1e18,-1};
if(p1 >= s1 && p2 <= s2) return drzewo[akt];
return min(get_min(akt*2,p1,(p1+p2)/2,s1,s2),get_min(akt*2+1,(p1+p2)/2+1,p2,s1,s2));
}
void upd(int v)
{
drzewo[v] = min(drzewo[v*2+1],drzewo[v*2]);
if(v != 1) upd(v/2);
}
void change(int ind, ll x)
{
drzewo[tree_siz/2+ind+1] = {x,ind};
upd((tree_siz/2+1+ind)/2);
}
};
segtree tree_right;
segtree tree_left;
ll P[500'001];
ll E[500'001];
bool used[500'001];
int main()
{
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
//random_start();
int n;
cin >> n;
map<int,int> Em;
rep(i,n)
{
int x,e;
cin >> x >> e;
Em[x] = max(Em[x],e);
}
n = siz(Em);
int cur = 0;
forall(it,Em)
{
P[cur] = it.ff;
E[cur] = it.ss;
cur++;
}
vector<pii> sort_vert;
rep(i,n) sort_vert.pb({E[i],i});
sort(all(sort_vert));
reverse(all(sort_vert));
rep(i,n) tree_right.change(i,P[i] + E[i]);
rep(i,n) tree_left.change(i,-P[i] + E[i]);
int ans = 0;
forall(it,sort_vert)
{
if(!used[it.ss])
{
tree_right.change(it.ss,1e18);
tree_left.change(it.ss,1e18);
ans++;
while(true)
{
pll t = tree_right.get_min(1,0,tree_siz/2,it.ss,n-1);
t.ff += -P[it.ss]-E[it.ss];
if(t.ff <= 0)
{
used[t.ss] = 1;
tree_right.change(t.ss,1e18);
tree_left.change(t.ss,1e18);
}
else break;
}
while(true)
{
pll t = tree_left.get_min(1,0,tree_siz/2,0,it.ss);
t.ff += P[it.ss]-E[it.ss];
if(t.ff <= 0)
{
used[t.ss] = 1;
tree_right.change(t.ss,1e18);
tree_left.change(t.ss,1e18);
}
else break;
}
}
}
cout << ans << "\n";
}
