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#include <bits/stdc++.h>
using namespace std;
#define l second
#define r first
typedef pair<int, int> PII;
const int INF = 0x3f3f3f3f;
const int N = 1e5 + 10;
int n;
PII a[N];
/*
由于pair会自动以first升序排列所以用pair就不用自己重载小于运算符，至于first和second的先后关系其实没什么意义。
只要在输入/存储时交换一下x,y顺序即可，如果觉得容易混可以直接定义l为second,r为first就不会混了，同理以左端点排序的题一样
*/
int res, ed = -INF;
int main() {
cin >> n;
for (int i = 0; i < n; i++) {
int x, y;
cin >> x >> y;
a[i] = {y, x};
}
sort(a, a + n);
if (a[i].l > ed) {
res++;
ed = a[i].r;
cout << res << endl;
return 0;
