#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;
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;
}
// The key insight: we want to place rods on buildings that protect the greatest range to the right
// We process buildings from left to right and place a rod when necessary
int rod_count = 0;
int i = 0;
while (i < n) {
// Place a new rod
rod_count++;
// Find the building that extends protection the furthest to the right
ll max_protection = -1;
// j is the candidate building for placing the rod
int j = i;
while (j < n && buildings[j].first - buildings[i].first <= buildings[j].second - buildings[i].second) {
// Calculate how far right this rod can protect:
// x + y represents the maximum x-coordinate that can be protected
// (if we go further right, the height difference would exceed the x difference)
ll protection_reach = buildings[j].first + buildings[j].second;
if (protection_reach > max_protection) {
max_protection = protection_reach;
}
j++;
}
// Skip all buildings that are protected by this rod
while (i < n && buildings[i].first <= max_protection - buildings[i].second) {
i++;
}
}
cout << rod_count << endl;
return 0;
}
