#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int n;
int ans;
vector<vector<int>> v;
void solve() {
int start = v[n-1][0];
ans ++;
for(int i=n-2; i>=0; i--) {
if(v[i][1]<=start) {
ans++;
start = v[i][0];
}
}
}
int main() {
cin >> n;
int start, end;
for(int i=0; i<n; i++) {
cin >> start >> end;
vector<int> temp;
temp.push_back(start);
temp.push_back(end);
v.push_back(temp);
}
sort(v.begin(), v.end());
solve();
cout << ans;
return 0;
}
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