#include <iostream> #include <algorithm> using namespace std; struct gio { int s; int f; } typedef timeh; int cmp (timeh a, timeh b) { if (a.f>b.f) return 0; return 1; } int main () { //IN; timeh h[10004]; int n; cin>>n; for (int i=0; i<n; i++) { cin>>h[i].s>>h[i].f; } //OUT; sort (h, h+n, cmp); int count=0; int next=0; int x=h[0].s; for (int i=0; i<n; i++) { if (x<=h[i].s) { count++; x=h[i].f; } } cout<<count; return 0; }