#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
// Fast I/O setup
static auto __ = []() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
return nullptr;
}();
typedef long long ll;
// Check if building at position j can protect building at position k
inline bool canProtect(const vector<pair<ll, ll>>& buildings, int j, int k) {
return abs(buildings[j].first - buildings[k].first) <= buildings[j].second - buildings[k].second;
}
int main() {
int n;
cin >> n;
vector<pair<ll, ll>> buildings(n);
for (int i = 0; i < n; i++) {
cin >> buildings[i].first >> buildings[i].second;
}
int rodCount = 0;
int i = 0;
while (i < n) {
// Need a new rod to protect building i
rodCount++;
// Find the building that will allow us to protect the furthest to the right
int maxReach = i;
for (int j = i; j < n; j++) {
// Check if a rod at j can protect building i
if (!canProtect(buildings, j, i)) {
break; // Buildings further right can't protect i either
}
// Find how far to the right a rod at j can protect
int k = maxReach;
while (k + 1 < n && canProtect(buildings, j, k + 1)) {
k++;
}
maxReach = max(maxReach, k);
}
// Skip to the next unprotected building
i = maxReach + 1;
}
cout << rodCount << endl;
return 0;
}
