#include <bits/stdc++.h>
#include <queue>
using namespace std;
#define lf "\n"
#define ff endl
#define _ << ' ' <<
#define all(x) begin(x),end(x)
#define rall(x) rbegin(x),rend(x)
#define infos(str) do { fprintf(stderr, str"\n"); } while(0)
#define infor(str, ...) do { fprintf(stderr, str, __VA_ARGS__); } while(0)
#define infof(str, ...) do { fprintf(stderr, str"\n", __VA_ARGS__); } while(0)
#ifndef DEBUG
#undef infos
#undef infor
#undef infof
#define infos(str)
#define infor(str, ...)
#define infof(str, ...)
#endif
using ll = long long;
constexpr int LOG = 20;
constexpr int MOD = 1e9+7;
constexpr int MAXN = 1e5+7;
int main(void) {
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int N; cin >> N;
vector<array<int, 2>> V(N);
for(int i = 0; i < N; ++i) {
auto &[l, r] = V[i];
cin >> l >> r;
l = max(0, i - l);
r = min(i + r, N);
}
vector<int> nxt(N, N);
priority_queue<int> q;
vector<vector<int>> psh(N);
for(int i = 0; i < N; ++i) {
while(!q.empty() && -q.top() < V[i][0])
nxt[-q.top()] = i, q.pop();
if(V[i][1] < N)
psh[V[i][1]].push_back(i);
for(auto v: psh[i])
q.push(-v);
}
vector<int> dp(N + 1);
dp[0] = dp[nxt[0]] = 1;
for(int i = 1; i < N; ++i) {
dp[i]++;
int r = nxt[i];
dp[r] = max(dp[r], dp[i]);
dp[i] = max(dp[i], dp[i - 1]);
}
cout << max(dp[N], dp[N - 1]) << lf;
}
