#include <bits/stdc++.h>
using namespace std;
int main() {
    vector<pair<int, int>> divisionArray;
    int n;
    int ans = 0;
    int stPointer = 0;
    int endPointer = INT32_MAX;
    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        int tempSt, tempEnd;
        scanf("%d %d", &tempSt, &tempEnd);
        divisionArray.push_back(pair<int, int>(tempSt, tempEnd));
    }
    sort(divisionArray.begin(), divisionArray.end());
    for (auto start : divisionArray) {
        if (start.first > endPointer) {
            ans++;
            stPointer = start.first;
            endPointer = start.second;
        }
        endPointer = start.second < endPointer ? start.second : endPointer;
    }
    printf("%d", ans + 1);
    return 0;
}