#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
signed main() {
cin.tie(0); ios::sync_with_stdio(false);
ll N;
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), B(N+5, 1e18); // B[k] = min j such that dp[j] >= k
dp[0] = 1;
B[0] = -1;
todo[R[0] + 1].push_back(0);
for(ll i = 1; i < N; i++) {
for(ll j: todo[i]) B[dp[j]] = min(B[dp[j]], j);
ll lo = 0, hi = N;
while(lo < hi - 1) {
ll mid = (lo + hi) / 2;
if (B[mid] < i-L[i]) lo = mid;
else hi = mid;
}
dp[i] = 1 + lo;
todo[i + R[i] + 1].push_back(i);
}
cout << *max_element(all(dp));
}
