#include <iostream>
#include <vector>
using namespace std;
#define int long long
#define pi pair<int,int>
const int INF = 1e9;
int log2_ceil(int n){
return 63 - __builtin_clzll(n) + (__builtin_popcountll(n) != 1);
}
inline int L(int node){
return 2*node;
}
inline int R(int node){
return 2*node + 1;
}
struct segment_tree {
int numElements, N;
vector<int> st;
segment_tree(int sz) : numElements(sz) {
N = (1 << log2_ceil(numElements));
st.assign(2*N, -INF);
for (int i=0; i<numElements; ++i) st[i+N] = 0;
for (int i=1; i<N; ++i) st[i] = max(st[L(i)], st[R(i)]);;
}
void update(int pos, int val){
if (pos >= numElements) return;
pos += N;
st[pos] = val;
pos /= 2;
while(pos >= 1){
st[pos] = max(st[L(pos)], st[R(pos)]);
pos /= 2;
}
}
int query(int node, int l, int r, int a, int b){
if (b < l || r < a) return -INF;
if (a <= l && r <= b) {
return st[node];
}
int m = (l+r)/2;
int res=-INF;
if (a <= m){
res = max(res, query(L(node), l, m, a, b));
}
if (b >= m+1){
res = max(res, query(R(node), m+1, r, a, b));
}
return res;
}
int query(int a, int b){
if (b < 0) return 0;
return query(1, 0, N-1, a, b);
}
};
void solve(){
int N; cin >> N;
vector<pi> tulips(N);
for (pi & par : tulips) cin >> par.first >> par.second;
vector<vector<pi> > pendUpdates(N);
vector<int> dp(N);
segment_tree ST(N);
for (int i=0; i<N; ++i){
int mx = max(0LL, ST.query(0, i-tulips[i].first-1)) + 1;
dp[i] = mx;
int rPos = i + tulips[i].second;
if (rPos < N) pendUpdates[rPos].push_back(pi(i, mx));
for (pi par : pendUpdates[i]){
ST.update(par.first, par.second);
}
}
int res = 0;
for (int n : dp) res = max(res, n);
cout << res << '\n';
}
signed main(){
ios::sync_with_stdio(false);
cin.tie(NULL);
solve();
return 0;
}
