#include <bits/stdc++.h>

#define For(x, y, z) for (int x = y, x##E = z; x <= x##E; ++x)
#define Rof(x, y, z) for (int x = y, x##E = z; x >= x##E; --x)
#define Eor(u) for (int i = head[u]; i; i = nxt[i])
#define SZ(x) (int(x.size()))
#define pb push_back

using namespace std;
using i64 = long long;
using ull = unsigned long long;
using pii = pair<int, int>;

// char buf[(1<<21)+5],*p1,*p2;
// #define getchar() (p1==p2&&(p2=(p1=buf)+fread(buf,1,1<<21,stdin),p1==p2)?EOF:*p1++)

inline int read() {
	int x = 0, f = 0; char ch = getchar();
	while (!isdigit(ch)) f |= (ch == '-'), ch = getchar();
	while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar();
	return f ? -x : x;
}
int __stk[128], __tp;
inline void put(i64 x) {
	if (x < 0) putchar('-'), x = -x;
	do { __stk[++__tp] = x % 10, x /= 10; } while (x);
	while (__tp) putchar(__stk[__tp--] + '0');
}

const int mod = 998244353;
inline int ksm(int x, int y, int res = 1) {
	for ( ; y; y >>= 1, x = 1ll * x * x % mod)
		(y & 1) && (res = 1ll * res * x % mod);
	return res;
}
inline int inv(int x) { return ksm(x, mod - 2); }
inline int gcd(int a, int b) { if (b) while ((a %= b) && (b %= a)); return a | b; }
inline void add(int &x, int y) { (x += y) >= mod && (x -= mod); }
inline void Min(int &x, int y) { (y < x) && (x = y); }
inline void Max(int &x, int y) { (y > x) && (x = y); }

const int N = 2e6 + 1000;

struct BIT{
    int t[N], n, lg; void init(int nn) { For(i, 0, n = nn) t[i] = 0; lg = log2(n); }
    void Add(int x, int y) { for (; x <= n; x += x & -x) t[x] += y; }
    int operator[](int x){ int y = 0; for (; x; x -= x & -x) y += t[x]; return y; }
    int find(int v) {
        int p = 0, sum = 0; Rof(i, lg, 0) if ((p | (1 << i)) <= n 
        && sum + t[p | (1 << i)] <= v) p |= 1 << i, sum += t[p]; return p;
    }
}f, pos;
int n, L[N], R[N], p[N];

signed main() {
	// freopen("lis.in", "r", stdin);
	// freopen("lis.out", "w", stdout);

    n = read(), f.init(1e6 + n + 2), pos.init(1e6);
    For(i, 1, n) L[i] = read(), R[i] = read(), ++p[max(L[i] - 1, 1)];
    For(i, 1, 1e6) p[i] += p[i - 1] + 1;
    
    For(i, 1, n) {
        pos.Add(max(L[i] - 1, 1), 1), pos.Add(R[i] + 1, -1);
        int l = p[L[i]] - pos[L[i]], r = p[R[i]] - pos[R[i]];
        f.Add(l, 1), f.Add(f.find(f[r]) + 1, -1);
    }
    
	cout << f[1e6];
	return 0;
}