#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
#if defined(__GNUC__) || defined(__clang__)
#pragma GCC optimize("Ofast,unroll-loops,inline-functions,no-stack-protector")
#pragma GCC target("avx2,fma,tune=native")
#pragma clang loop vectorize(enable)
#pragma clang loop interleave(enable)
#endif
#define int long long
#define sz(x) (int)x.size()
#define F first
#define S second
#define pb push_back
#define nl '\n'
#define o_set tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update>
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef pair<int, int> pii;
void file( string s = "" )
{
if( s.empty() )
return;
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
}
const int N = 2e5 + 2;
const int N1 = 1e6 + 2;
const int inf = 1e9 + 2;
const int INF = 1e18 + 2;
const int mod = 1e9 + 7;
int T = 1, t[4 * N];
void upd( int v, int tl, int tr, int p, int x )
{
if( tl == tr )
{
t[v] = max(t[v], x);
return;
}
int m = (tl + tr) / 2;
if( p <= m )
upd(v + v, tl, m, p, x);
else
upd(v + v + 1, m + 1, tr, p, x);
t[v] = max(t[v + v], t[v + v + 1]);
}
int get( int v, int tl, int tr, int l, int r )
{
if( r < tl || tr < l )
return 0;
if( l <= tl && tr <= r )
return t[v];
int m = (tl + tr) / 2;
return max(get(v + v, tl, m, l, r), get(v + v + 1, m + 1, tr, l, r));
}
void solve()
{
int n;
cin >>n;
int l[n + 1], r[n + 1];
vector< int > dp(n + 1), v[n + 1];
for( int i = 1; i <= n; ++i )
{
cin >>l[i] >>r[i];
l[i] = max(1ll, i - l[i]);
r[i] = min(n, i + r[i]);
v[r[i]].pb(i);
}
int ans = 0;
for( int i = 1; i <= n; ++i )
{
int x = 0;
if( l[i] > 1 )
x = get(1, 1, n, 1, l[i] - 1);
dp[i] = x + 1;
for( auto j: v[i] )
upd(1, 1, n, j, dp[j]);
}
for( int i = 1; i <= n; ++i )
ans = max(ans, dp[i]);
cout <<ans;
}
signed main()
{
file("");
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// cin >>T;
while( T-- )
solve();
}
