#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define pb push_back
#define ff first
#define ss second
struct SEGTREE{
ll n;
vector<ll> tree;
void upd(ll N, ll L, ll R, ll i, ll s){
if(i < L || i > R)return;
if(L == R){
tree[N] = s;
return;
}
ll M = (L + R) / 2;
upd(2 * N + 1, L, M, i, s);
upd(2 * N + 2, M + 1, R, i, s);
tree[N] = max(tree[2 * N + 1], tree[2 * N + 2]);
}
ll get(ll N, ll L, ll R, ll l, ll r){
if(L >= l && R <= r)return tree[N];
if(L > r || R < l)return 0;
ll M = (L + R) / 2;
return max(get(2 * N + 1, L, M, l, r), get(2 * N + 2, M + 1, R, l, r));
}
SEGTREE(ll sz){
n = 1;
while(n < sz)n *= 2;
tree = vector<ll>(2 * n, 0);
}
void upd(ll i, ll s){
upd(0, 0, n - 1, i, s);
}
ll get(ll l, ll r){
return get(0, 0, n - 1, l, r);
}
};
void solve(){
int n; cin >> n;
vector<pair<int, int>> a(n + 1);
SEGTREE seg(n+1);
for(int i = 1; i <= n; ++i){
cin >> a[i].ff >> a[i].ss;
}
vector<ll> dp(n * 2 + 2);
vector<vector<pair<int,int>>>st(n*2+2);
for(int i = 1; i <= n; ++i){
for(auto&j:st[i]){
seg.upd(j.ff,j.ss);
}
dp[i]= seg.get(0,i-a[i].ff-1)+1;
st[i+a[i].ss+1].pb({i,dp[i]});
}
cout<<*max_element(begin(dp),end(dp)) <<"\n";
}
//1 1 0 1 0 1 0 0 1 1 1
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL), cout.tie(NULL);
ll t = 1;
//cin >> t;
while(t--){
solve();
}
}
