#pragma GCC optimize("O3")
#include <bits/stdc++.h>
using namespace std;
constexpr int R = 1 << 19, inf = 2e9 + 7;
set<pair<int, int>> tree[R * 2][2];
void add(int pos, int tp, pair<int, int> val) {
for (pos += R; pos > 0; pos /= 2) {
tree[pos][tp].insert(val);
}
}
void del(int pos, int tp, pair<int, int> val) {
for (pos += R; pos > 0; pos /= 2) {
tree[pos][tp].erase(val);
}
}
pair<int, int> get_min(int l, int r, int tp) {
l += R;
r += R;
pair<int, int> ans = {inf, -1};
while (l < r) {
if (l & 1) {
if (!tree[l][tp].empty()) {
ans = min(ans, *tree[l][tp].begin());
}
l++;
}
if (r & 1) {
--r;
if (!tree[r][tp].empty()) {
ans = min(ans, *tree[r][tp].begin());
}
}
l >>= 1;
r >>= 1;
}
return ans;
}
pair<int, int> get_max(int l, int r, int tp) {
l += R;
r += R;
pair<int, int> ans = {-inf, -1};
while (l < r) {
if (l & 1) {
if (!tree[l][tp].empty()) {
ans = max(ans, *tree[l][tp].rbegin());
}
l++;
}
if (r & 1) {
--r;
if (!tree[r][tp].empty()) {
ans = max(ans, *tree[r][tp].rbegin());
}
}
l >>= 1;
r >>= 1;
}
return ans;
}
void solve() {
int n;
cin >> n;
vector<int> x(n), e(n);
vector<pair<int, int>> ord;
for (int i = 0; i < n; ++i) {
cin >> x[i] >> e[i];
}
vector<int> b = x;
sort(b.begin(), b.end());
b.resize(unique(b.begin(), b.end()) - b.begin());
for (int i = 0; i < n; ++i) {
x[i] = lower_bound(b.begin(), b.end(), x[i]) - b.begin();
add(x[i], 0, {b[x[i]] - e[i], i});
add(x[i], 1, {b[x[i]] + e[i], i});
ord.emplace_back(e[i], i);
}
sort(ord.rbegin(), ord.rend());
int ans = 0;
vector<int> used(n);
for (auto [val, ind] : ord) {
if (used[ind]) {
continue;
}
used[ind] = 1;
ans++;
del(x[ind], 0, {b[x[ind]] - e[ind], ind});
del(x[ind], 1, {b[x[ind]] + e[ind], ind});
while (true) {
auto p = get_max(0, x[ind] + 1, 0);
if (p.second == -1 || p.first < b[x[ind]] - e[ind]) {
break;
}
used[p.second] = 1;
del(x[p.second], 0, {b[x[p.second]] - e[p.second], p.second});
del(x[p.second], 1, {b[x[p.second]] + e[p.second], p.second});
}
while (true) {
auto p = get_min(x[ind], R, 1);
if (p.second == -1 || p.first > b[x[ind]] + e[ind]) {
break;
}
used[p.second] = 1;
del(x[p.second], 0, {b[x[p.second]] - e[p.second], p.second});
del(x[p.second], 1, {b[x[p.second]] + e[p.second], p.second});
}
}
cout << ans << '\n';
}
signed main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int t = 1;
// cin >> t;
while (t--) {
solve();
}
return 0;
}
