#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] = 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 query(ll l, ll r, ll tl = 0, ll tr = N-1, ll i = 1) {
if (l > r) return 0;
if (tl == l && tr == r) return tree[i];
ll tm = (tl + tr) / 2;
return max(query(l, min(r, tm), tl, tm, i * 2), query(max(l, tm + 1), r, tm + 1, tr, i * 2 + 1));
}
signed main() {
cin.tie(0); ios::sync_with_stdio(false);
cin >> N;
tree.resize(N*4);
vector<ll> L(N), R(N), dp(N);
vector<vector<ll>> todo(N*2);
FOR(i, N) cin >> L[i] >> R[i];
for(ll i = 0; i < N; i++) {
for(ll j: todo[i]) {
update(dp[j], j);
}
dp[i] = 1 + query(0, i-L[i]-1);
todo[i+R[i]+1].push_back(i);
}
cout << dp[N-1];
}
