#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;
typedef long long ll;

class Interval {
public:
    int left, right;
    Interval(int l, int r) : left(l), right(r) {}
    Interval() {}
    friend bool operator<(const Interval& A, const Interval& B) { return (A.right < B.right); }
};

const int MAX = 1e6 + 5;
Interval intervals[MAX];

int main() {
    // freopen("test.txt", "r", stdin);
    int n, m;
    while (scanf("%d", &n) != EOF) {
        // 输入
        for (int i = 1; i <= n; i++) {
            scanf("%d %d", &intervals[i].left, &intervals[i].right);
        }
        // 排序
        sort(intervals + 1, intervals + 1 + n);
        // 求解
        int res = 0;
        int pos = 0;
        for (int i = 1; i <= n; i++) {
            if (pos < intervals[i].left) {
                pos = intervals[i].right;
                res++;
            }
        }
        // 输出
        printf("%d\n", res);
    }
    return 0;
}