#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define inf INT_MAX
#define fr(i,l,r) for (i=(l); i<=(r); i++)
#define rfr(i,l,r) for (i=(l); i>=(r); i--)
template<typename T>inline void read(T &n){
    T w=1; n=0; char ch=getchar();
    while (!isdigit(ch) && ch!=EOF){ if (ch=='-') w=-1; ch=getchar(); }
    while (isdigit(ch) && ch!=EOF){ n=(n<<3)+(n<<1)+(ch&15); ch=getchar(); }
    n*=w;
}
template<typename T>inline void write(T x){
    if (x==0){ putchar('0'); return ; }
    T tmp;
    if (x>0) tmp=x;
    else tmp=-x;
    if (x<0) putchar('-');
    char F[105];
    long long cnt=0;
    while (tmp){
        F[++cnt]=tmp%10+48;
        tmp/=10;
    }
    while (cnt) putchar(F[cnt--]);
}
#define Min(x,y) x = min(x,y)
#define Max(x,y) x = max(x,y)
//基础配置=================================================================================
const ll N = 500005;
ll n,m,ans=0,x,y,l,r,s,z;
struct infor{
    ll l,r;
};
infor a[N],b[N];
bool cmp1(infor x,infor y){
    if (x.r==y.r) return x.l<y.l;
    else return x.r<y.r;
}
bool cmp2(infor x,infor y){
    if (x.l==y.l) return x.r>y.r;
    else return x.l>y.l;
    // return x.l>y.l;
}
inline bool check(ll s){
    ll i,j;
    for (ll i=1, j=s; i<=s; i++,j--)
        if (b[j].l<=a[i].r) return false;
    return true;
}
int main(){
	// freopen("ex_interval2.in","r",stdin);
//	freopen(".out","w",stdout);
    ll i,j;
    read(n);
    fr(i,1,n) read(a[i].l), read(a[i].r), b[i] = a[i];
    sort(a+1,a+1+n,cmp1);
    sort(b+1,b+1+n,cmp2);
    // printf("\n a :\n");
    // fr(i,1,n) printf("%lld : %lld ~ %lld\n",i,a[i].l,a[i].r);
    // printf("\n b :\n");
    // fr(i,1,n) printf("%lld : %lld ~ %lld\n",i,b[i].l,b[i].r);
    ll l = 0, r = n/2;
    while (l<=r){
        ll mid = (l+r)>>1;
        if (check(mid)) l = mid+1;
        else r = mid-1;
    }
    write(r);
    return 0;
}
//g++ a.cpp -o a -Wall -Wl,--stack=512000000 -std=c++11 -O2