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 1 #include<bits/stdc++.h>

 2 using namespace std;

 3 const int maxn=1e6+10;

 4 struct node

 5 {

 6     int l,r;

 7 }sz[maxn];

 8 int n,ans;

 9 bool cmp(node x,node y)

10 {

11     return x.r<y.r;

12 }

13 int main()

14 {

15     scanf("%d",&n);

16     for(int i=1;i<=n;++i)scanf("%d%d",&sz[i].l,&sz[i].r);

17     sort(sz+1,sz+1+n,cmp);

18     int rr=-1;

19     for(int i=1;i<=n;++i)

20     {

21         if(sz[i].l>=rr)

22         {

23             ans++;

24             rr=sz[i].r;

25         }

26     }

27     cout<<ans;

28     return 0;

29 }