#include<bits/stdc++.h> using namespace std; struct node { int north; int south; }; node a[200005]; int n,i,d[200005],len,temp; bool cmp(node x,node y) { return x.north<y.north; } int main () { scanf("%d",&n); for(i=1;i<=n;i++) { scanf("%d",&a[i].north); scanf("%d",&a[i].south); } sort(a+1,a+1+n,cmp); d[++len]=a[1].south; for(i=2;i<=n;i++) { int dbzjrQwQ=upper_bound(d+1,d+len+1,a[i].south)-d; d[dbzjrQwQ]=a[i].south; if(dbzjrQwQ>len) { len++; } } printf("%d",len); return 0; }