#include<bits/stdc++.h>
#define ll long long
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
using namespace std;
const int N=2e5+5;
int l[N], r[N];
int dp[N];
vector< int > u[N];
int tree[4*N];
void update(int v, int l, int r, int p, int x){
if(p<l || p>r) return;
if(l==p && p==r){
tree[v]=x;
}
else{
int mid=(l+r)/2;
update(2*v, l, mid, p, x);
update(2*v+1, mid+1, r, p, x);
tree[v]=max(tree[2*v], tree[2*v+1]);
}
}
int query(int v, int l, int r, int p){
if(p<l) return 0;
if(r<=p){
return tree[v];
}
int mid=(l+r)/2;
return max(query(2*v, l, mid, p), query(2*v+1, mid+1, r, p));
}
int main(){
int n, i, j, un, ans;
scanf("%d",&n);
for(i=1; i<=n; i++){
scanf("%d",&l[i]);
scanf("%d",&r[i]);
r[i]=min(i+r[i], n);
l[i]=max(1, i-l[i]);
u[r[i]+1].pb(i);
}
dp[0]=0;
ans=0;
for(i=1; i<=n; i++){
un=u[i].size();
for(j=0; j<un; j++){
update(1, 1, n, u[i][j], dp[u[i][j]]);
}
dp[i]=query(1, 1, n, l[i]-1)+1;
ans=max(ans, dp[i]);
}
printf("%d\n", ans);
return 0;
}
