#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
// loal is the cutest girl
#define ll long long
#define ld long double
#define pow2(x) (x)*(x)
#define le left
#define ri right
#define fi first
#define se second
#define pb push_back
#define all(v) v.begin(), v.end()
#define pii pair<int, int>
#define pll pair<long long, long long>
#define isvowel(x) (x) == 'a' || (x) == 'i' || (x) == 'u' || (x) == 'e' || (x) == 'o'
#define ordered_set tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update>
const ld EPS = 1e-9;
const ld PI = 3.141592653589793238462643383279502884197169399375105820974944;
const int maxn = 2e5+5;
int n;
pii a[maxn];
signed main() {
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n;
for (int i = 0; i < n; i++) {
cin >> a[i].fi >> a[i].se;
}
int dp[n][2];
vector<int> ls[n];
set<int> active;
dp[0][0] = 0;
dp[0][1] = 1;
if (a[0].se > 0) {if (a[0].se < n) ls[a[0].se].pb(0);}
else active.insert(0);
for (int i = 1; i < n; i++) {
dp[i][0] = max(dp[i-1][1], dp[i-1][0]);
// find rightmost possible
auto it = active.lower_bound(i-a[i].fi);
if (it == active.begin()) dp[i][1] = 1;
else {
it--;
dp[i][1] = 1+max(dp[*it][1], dp[*it][0]);
}
if (i+a[i].se < n)
ls[i+a[i].se].pb(i);
for (auto j : ls[i]) active.insert(j);
}
cout << max(dp[n-1][1], dp[n-1][0]);
return 0;
}
