#include<bits/stdc++.h>

 #define IOS ios::sync_with_stdio(false);//不可再使用scanf printf

 #define Max(a, b) ((a) > (b) ? (a) : (b))//禁用于函数，会超时

 #define Min(a, b) ((a) < (b) ? (a) : (b))

 #define Mem(a) memset(a, 0, sizeof(a))

 #define Dis(x, y, x1, y1) ((x - x1) * (x - x1) + (y - y1) * (y - y1))

 #define MID(l, r) ((l) + ((r) - (l)) / 2)

 #define lson ((o)<<1)

 #define rson ((o)<<1|1)

 #define Accepted 0

 #pragma comment(linker, "/STACK:102400000,102400000")//栈外挂

 using namespace std;

 inline int read()

 {

     int x=,f=;char ch=getchar();

     while (ch<''||ch>''){if (ch=='-') f=-;ch=getchar();}

     while (ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}

     return x*f;

 }

 typedef long long ll;

 const int maxn =  + ;

 const int MOD = ;//const引用更快，宏定义也更快

 const int INF = 1e9 + ;

 const double eps = 1e-;

 stack<int>q;

 int main()

 {

     int n, ans = , x, y;

     scanf("%d", &n);

     for(int i = ; i <= n; i++)

     {

         scanf("%d%d", &x, &y);

         while(!q.empty() && q.top() > y)

         {

             q.pop();

             ans++;

         }

         if(!q.empty() && q.top() == y)continue;

         q.push(y);

     }

     ans += q.size();

     printf("%d\n", ans);

     return Accepted;

 }