#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define FOR(i,N) for(ll i = 0; i < N; i++)
#define all(x) (x).begin(), (x).end()
#define F first
#define S second
ll N;
vector<ll> tree;
void update(ll v, ll p, ll tl = 0, ll tr = N-1, ll i = 1) {
if (tl == tr) {tree[i] = min(tree[i], v); return ;}
ll tm = (tl + tr) / 2;
if (p <= tm) update(v, p, tl, tm, i * 2);
else update(v, p, tm + 1, tr, i * 2 + 1);
tree[i] = max(tree[i * 2], tree[i * 2 + 1]);
}
ll walk(ll x, ll tl = 0, ll tr = N-1, ll i = 1) {
if (tl == tr) return tl - 1;
ll tm = (tl + tr) / 2;
if (tree[i * 2] >= x) return walk(x, tl, tm, i * 2);
else return walk(x, tm + 1, tr, i * 2 + 1);
}
signed main() {
cin.tie(0); ios::sync_with_stdio(false);
cin >> N;
vector<ll> L(N), R(N);
FOR(i, N) cin >> L[i] >> R[i];
vector<vector<ll>> todo(N*2+5);
vector<ll> dp(N);
tree.resize(4*(N+5), 1e18); // tree[tl] = max j such that dp[j] > tl
dp[0] = 1;
update(-1, 0);
todo[R[0] + 1].push_back(0);
for(ll i = 1; i < N; i++) {
for(ll j: todo[i]) update(j, dp[j]);
dp[i] = 1 + walk(i - L[i]);
todo[i + R[i] + 1].push_back(i);
}
cout << *max_element(all(dp));
}
