
#include <bits/stdc++.h>
using namespace std;
struct node {
int s, e;
} a[100005];
bool cmp(node x, node y) {
return x.e < y.e;
}
int k, n;
int ans, x, y;
int main() {
cin >> k >> n;
for (int i = 0; i < n; i++) {
cin >> a[i].s >> a[i].e;
}
sort(a, a + n, cmp);
for (int i = 0; i < n; i++) {
if (a[i].e > k) continue;
if (a[i].s >= x) {
ans++;
x = a[i].e;
}
else if (a[i].s >= y) {
ans++;
y = a[i].e;
}
}
cout << ans << endl;
return 0;
}
敢问这代码哪错了


