DROPTEST

#define task "DROPTEST"
#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

using ll = long long;
using ld = long double;

constexpr int N = 1e6 + 5;
constexpr int Inf = 1e9 + 7;
int n, f[N];
int a[N], b[N];

void Read()
{
    cin >> n;

    for (int i = 1; i <= n; ++i)
        cin >> a[i] >> b[i];
}

void Solve()
{
    vector<int> s;
    int ans(0);

    a[n + 1] = b[n + 1] = -Inf;

    for (int i = 1, j = 0; i <= n + 1; ++i)
    {
        int maxn = 1;

        while (!s.empty() && a[s.back()] <= a[i])
        {
            if (j < (int)s.size())
                maxn = max(maxn, f[s.back()] + i - s.back());

            s.pop_back();
            j = min(j, (int)s.size());
        }

        s.emplace_back(i);

        while (j < (int)s.size() && a[s[j]] > b[i])
        {
            ans = max(ans, f[s[j]] + i - s[j] - 1);
            ++j;
        }

        f[i] = maxn;
    }

    cout << ans;
}

int32_t main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    if (fopen(task ".INP", "r"))
    {
        freopen(task ".INP", "r", stdin);
        freopen(task ".OUT", "w", stdout);
    }

    Read();
    Solve();
}