#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC optimize("unroll-loops,no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long ll;
typedef long double ld;
void fastscan(int &x)
{
bool neg=false;
register int c;
x =0;
c=getchar();
if(c=='-')
{
neg = true;
c=getchar();
}
for(;(c>47 && c<58);c=getchar())
x = (x<<1) + (x<<3) +c -48;
if(neg)
x *=-1;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
fastscan(n);
int arrx[n];
int arry[n];
for (int z=0;z<n;z++){
fastscan(arrx[z]);
fastscan(arry[z]);
}
stack <int> s;
for (int z=0;z<n;z++){
int a = arrx[z]-arry[z];
int b = arrx[z]+arry[z];
if (s.empty()){
s.emplace(z);
}
int c = arrx[s.top()]-arry[s.top()];
int d = arrx[s.top()]+arry[s.top()];
if (c <= a && b <= d) continue;
else{
while (a <= c && d <= b){
s.pop();
if (s.size() == 0) break;
c = arrx[s.top()]-arry[s.top()];
d = arrx[s.top()]+arry[s.top()];
}
s.emplace(z);
}
}
printf("%d",int(s.size()));
}
