#pragma target("arch=icelake-server")
#include <iostream>
#include <vector>
#include <algorithm>
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <stack>
#include <queue>
#include <cmath>
#include <random>
#include <chrono>
#include <iomanip>
#include <bitset>
using namespace std;
#define int long long
typedef long long ll;
typedef long double ld;
int log_ = 21;
int inf = 4000000007000000007;
long long mod = 998244353;
int p = 499;
int NADIYA = 39;
struct segment_tree
{
vector <int> tree;
int s = 1;
void init(int n)
{
s = 1;
while (s < n)
s *= 2;
tree.resize(2 * s , -inf);
}
void modif(int ind, int l, int r , int indx , int x)
{
if(r - l == 1)
{
tree[ind] = max(tree[ind], x);
return;
}
int m = (l + r) / 2;
if (indx < m)
modif(ind * 2 + 1, l, m, indx, x);
else
modif(ind * 2 + 2, m, r, indx, x);
tree[ind] = max(tree[ind * 2 + 1], tree[ind * 2 + 2]);
}
void modif(int indx, int x)
{
modif(0, 0, s, indx, x);
}
int get(int ind, int l, int r, int lx, int rx)
{
if ((lx <= l) and (r <= rx))
{
return tree[ind];
}
if ((rx <= l) or (r <= lx))
return -inf;
int m = (l + r) / 2;
int g1 = get(ind * 2 + 1, l, m, lx, rx);
int g2 = get(ind * 2 + 2, m, r, lx, rx);
return max(g1, g2);
}
int get(int lx, int rx)
{
return get(0, 0, s, lx, rx);
}
};
bool cmp(pair <int, int> a, pair <int, int> b)
{
if (a.second > b.second)
{
return true;
}
return false;
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int n;
cin >> n;
vector <pair <int, int>> vp(n);
for (int i = 0; i < n; i++)
cin >> vp[i].first >> vp[i].second;
sort(vp.begin(), vp.end(), cmp);
vector <pair <int, int>> vp_;
for (int i = 0; i < n; i++)
{
vp_.push_back({ vp[i].first , i });
}
sort(vp_.begin(), vp_.end());
int c = 0;
vector <int> x(n);
for (int i = 0; i < n; i++)
{
if (i > 0)
{
if (vp_[i - 1].first != vp_[i].first)
c++;
}
x[vp_[i].second] = c;
}
c++;
vector <int> y(c);
for (int i = 0; i < n; i++)
{
y[x[i]] = vp[i].first;
}
vector <int> p1(c);
for (int i = 0; i < c; i++)
{
p1[i] = y[i];
}
vector <int> p2(c);
for (int i = 0; i < c; i++)
{
p2[i] = -y[i];
}
segment_tree st1;
segment_tree st2;
st1.init(c);
st2.init(c);
int ans = 0;
for (int i = 0; i < n; i++)
{
int p = vp[i].first;
int e = vp[i].second;
int g = st1.get(0, x[i] + 1);
g -= p1[x[i]];
if (g >= e)
{
continue;
}
g = st2.get(x[i] , c);
g -= p2[x[i]];
if (g >= e)
{
continue;
}
ans++;
st1.modif(x[i], e + p1[x[i]]);
st2.modif(x[i], e + p2[x[i]]);
}
cout << ans;
}
/*5
1 2 1
2 3 1
2 4 1
1 5 4
*/
