#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
typedef tree<long long, null_type, less<long long>, rb_tree_tag, tree_order_statistics_node_update> ordered_set; // find_by_order(it return an iterator input is a value), order_of_key(input is index)
typedef tree<long long, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_multiset;
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
template <class T>
void Distinct(T &v, bool sorting = true)
{
if (sorting)
sort(begin(v), end(v));
v.resize(unique(begin(v), end(v)) - begin(v));
}
const int BUF_SZ = 1 << 15;
inline namespace Input
{
char buf[BUF_SZ];
int pos;
int len;
char next_char()
{
if (pos == len)
{
pos = 0;
len = (int)fread(buf, 1, BUF_SZ, stdin);
if (!len)
{
return EOF;
}
}
return buf[pos++];
}
int read_int()
{
int x;
char ch;
int sgn = 1;
while (!isdigit(ch = next_char()))
{
if (ch == '-')
{
sgn *= -1;
}
}
x = ch - '0';
while (isdigit(ch = next_char()))
{
x = x * 10 + (ch - '0');
}
return x * sgn;
}
} // namespace Input
inline namespace Output
{
char buf[BUF_SZ];
int pos;
void flush_out()
{
fwrite(buf, 1, pos, stdout);
pos = 0;
}
void write_char(char c)
{
if (pos == BUF_SZ)
{
flush_out();
}
buf[pos++] = c;
}
void write_int(int x)
{
static char num_buf[100];
if (x < 0)
{
write_char('-');
x *= -1;
}
int len = 0;
for (; x >= 10; x /= 10)
{
num_buf[len++] = (char)('0' + (x % 10));
}
write_char((char)('0' + x));
while (len)
{
write_char(num_buf[--len]);
}
write_char('\n');
}
// auto-flush output when program exits
void init_output() { assert(atexit(flush_out) == 0); }
} // namespace Output
const int sz = 10000010;
const int sz1 = 10000010;
int Fenwick[sz] = {0};
int long Fenwick1[sz1] = {0};
unordered_map<long long int, int> D1, D2;
// 1 BASED INDEXING
// ALWAYS DECLARE FENWICK TREE GLOBALLY
struct fenwicktree
{
int n;
vector<int> v;
fenwicktree(vector<int> A)
{
v.resize(A.size() + 1, 0);
n = A.size();
for (int i = 0; i < A.size(); i++)
Add(i + 1, A[i]);
}
int Sum(int i)
{
int answer = 0;
for (; i > 0; i -= (i & (-i)))
answer += Fenwick[i];
return answer;
}
void Add(int i, int x)
{
v[i] += x;
for (; i <= n; i += (i & (-i)))
Fenwick[i] += x;
}
void Replace(int i, int x)
{
int y = v[i];
v[i] = x;
for (; i <= n; i += (i & (-i)))
Fenwick[i] += x - y;
}
long long RangeSum(int l, int r)
{
return Sum(r) - Sum(l - 1);
}
};
// 1 BASED INDEXING
// ALWAYS DECLARE FENWICK TREE GLOBALLY
struct fenwicktree1
{
int n;
vector<int> v;
fenwicktree1(vector<int> A)
{
v.resize(A.size() + 1, 0);
n = A.size();
for (int i = 0; i < A.size(); i++)
Add(i + 1, A[i]);
}
int Sum(int i)
{
int answer = 0;
for (; i > 0; i -= (i & (-i)))
answer += Fenwick1[i];
return answer;
}
void Add(int i, int x)
{
v[i] += x;
for (; i <= n; i += (i & (-i)))
Fenwick1[i] += x;
}
void Replace(int i, int x)
{
int y = v[i];
v[i] = x;
for (; i <= n; i += (i & (-i)))
Fenwick1[i] += x - y;
}
long long RangeSum(int l, int r)
{
return Sum(r) - Sum(l - 1);
}
};
//----------------------------------------------------
void solve()
{
int n;
n = read_int();
vector<pair<int, int>> v(n);
for (int i = 0; i < n; i++)
{
int a, b;
a = read_int();
b = read_int();
v[i] = {b, a};
}
sort(begin(v), end(v));
reverse(begin(v), end(v));
int c1, c2;
{
vector<long long> a;
for (int i = 0; i < n; i++)
a.push_back(v[i].second - v[i].first);
Distinct(a);
for (int i = 0; i < a.size(); i++)
D1[a[i]] = i + 1;
c1 = a.size();
a.clear();
for (int i = 0; i < n; i++)
a.push_back(v[i].second + v[i].first);
Distinct(a);
c2 = a.size();
for (int i = 0; i < a.size(); i++)
D2[a[i]] = i + 1;
}
fenwicktree a(vector<int>(c1 + 5, 0));
fenwicktree1 b(vector<int>(c2 + 5, 0));
int answer = 0;
for (int i = 0; i < n; i++)
{
int d1 = v[i].second - v[i].first;
int d2 = v[i].second + v[i].first;
int p1 = a.RangeSum(1, D1[d1]);
int p2 = b.RangeSum(D2[d2], c2);
if (p1 + p2 - answer > 0)
continue;
answer++;
a.Add(D1[d1], 1);
b.Add(D2[d2], 1);
}
write_int(answer);
}
//----------------------------------------------------
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
init_output();
solve();
return 0;
}
//----------------------------------------------------
