#include <bits/stdc++.h>

using namespace std;
struct ok
{
    int fi, se;
};
bool ss(ok x, ok y)
{
    if (x.fi != y.fi) return (x.fi < y.fi);
    else return (x.se > y.se);
}
int main()
{
    int res = 1, i, j, n, tmp, x;
    ok a[1001];
    //freopen("test.inp","r",stdin);
    cin >> n;
    for (i = 1; i <= n; i++) cin >> a[i].fi >> a[i].se;
    sort(a+1, a+1+n, ss);
    for (i = 2; i <= n; i++)
    {
        tmp = 1;
        x = a[i].fi;
        for (j = i-1; j >= 1; j--) if (x > a[j].se)
        {
            tmp++;
            x = a[j].fi;
        }
        res = max(res, tmp);
    }
    cout << res;
    return 0;
}