#include <bits/stdc++.h> #define ii pair<int, int> #define fi first #define se second #define inf 0x3f3f3f3f3f3f3f3f using namespace std; using ll = long long; const ll mod=1e9+7; const int nx=1e7+5; int n, ans=0, cur=-1; ii a[nx]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); cin>>n; for(int i = 1; i <= n; i++) { cin>>a[i].fi>>a[i].se; if(cur==-1) { ans++; cur=i; continue; } if(a[i].fi-a[cur].fi<=a[i].se-a[cur].se) cur=i; else if(a[i].fi-a[cur].fi>a[cur].se-a[i].se) ans++, cur=i; } cout<<ans; }