/*DavitMarg*/
#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <string>
#include <cstring>
#include <map>
#include <set>
#include <queue>
#include <iomanip>
#include <bitset>
#include <stack>
#include <cassert>
#include <iterator>
#include <ctype.h>
#include <fstream>
#define mod 1000000007ll
#define LL long long
#define LD long double
#define MP make_pair
#define PB push_back
#define all(v) v.begin (),v.end()
using namespace std;
int n,cnt,vin[200005], vout[200005],used[200005];
vector<pair<int, int>> p;
bool can;
void dfs(int v)
{
used[v] = 1;
cnt++;
int l, r, m, pos = n;
l = 0;
r = n - 1;
while (l <= r)
{
m = (l + r) / 2;
if (p[m].first >= p[v].second)
{
r = m - 1;
pos = m;
}
else
l = m + 1;
}
vout[v] += (n - pos) - (pos <= v);
vin[pos]++;
for (int to = pos; to < n && cnt<n; to++)
{
if (used[to])
continue;
dfs(to);
}
}
int Main()
{
sort(all(p));
dfs(0);
if (cnt != n)
{
can = 1;
return 0;
}
int mt = 0, du = 0;
for (int i = 0; i < n; i++)
{
mt += (vin[i]==0);
du += (vout[i]==0);
}
if (mt > 1 || du > 1)
can = 1;
return 0;
}
LL plan_roller_coaster(vector<int> S, vector<int> T)
{
n = S.size();
while (!S.empty())
{
p.PB(MP(S.back(), T.back()));
S.pop_back();
T.pop_back();
}
Main();
return can;
}
#ifdef death
int main()
{
int N;
vector<int> S,T;
cin >> N;
for (int i = 0; i < N; i++)
{
S.PB(0);
cin >> S.back();
T.PB(0);
cin >> T.back();
}
cout << plan_roller_coaster(S,T) << endl;
return 0;
}
#endif
/*
*/
