#include<bits/stdc++.h>
using namespace std;
using ll = long long;
const int boro = 200005;
ll vag = 1000000007;
int n , l[boro] , r[boro] , ans[boro] , curans , curpos , uttor;
vector<int> notun[boro];
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
curans = 0;
curpos = -10000000;
uttor = 0;
cin >> n;
for( int z = 0; z <= n + 1; z++ ){
notun[z].clear();
}
for( int z = 1; z <= n; z++ ){
cin >> l[z] >> r[z];
for( auto it : notun[z] ){
if( ans[it] > curans ){
curans = ans[it];
curpos = it;
}
else if( ans[it] == curans && it < curpos ){
curpos = it;
}
}
if( z - l[z] > curpos ){
ans[z] = curans + 1;
notun[min( (n + 1) , z + r[z] + 1)].push_back(z);
uttor = max( uttor , ans[z] );
}
}
cout << uttor << "\n";
return 0;
}
