#include <iostream> #include <algorithm> using namespace std; int l[110], r[110]; int main() { int n, len = -1; cin >> n; while(n) { for(int i = 1; i <= n; i++) {cin >> l[i] >> r[i]; len = max(len, r[i]);} sort(r + 1, r + n + 1); int cnt = 1, c = r[1]; for(int i = 2; i <= n; i++) { if(l[i] >= c) { cnt++; c = r[i]; } } cout << cnt << endl; cin >> n; } return 0; }