#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;
inline int readInt() {
int x = 0;
char ch = getchar();
while (ch < '0' || ch > '9') ch = getchar();
while (ch >= '0' && ch <= '9'){
x = (x << 3) + (x << 1) + ch - '0';
ch = getchar();
}
return x;
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int n;
n = readInt();
int arrx[n];
int arry[n];
for (int z=0;z<n;z++){
arrx[z] = readInt();
arry[z] = readInt();
}
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.push(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.push(z);
}
}
printf("%d",int(s.size()));
}
