# int compar (const void*p, const void*q)   
# {     
#     interval *pp=(interval*)p, *qq=(interval*)q;  
#     interval x=*pp, y=*qq;  
#     if(x.b<y.b)  
#         return -1;  
#     if(x.b>y.b)  
#         return 1;  
#     return 0;     
#   
# }  
#   
# int main()  
# {   interval v[N];  
#     int n,dr,i,j,rez=1;  
#     freopen("int.in", "r", stdin);  
#     freopen("int.out", "w",stdout);  
#     scanf("%d", &n);  
#     for(i=0;i<n;i++)  
#         scanf("%d%d", &v[i].a, &v[i].b);  
#     qsort(v,n,sizeof(v[0]),compar);  
#           
#     dr=v[0].b;  
#     for(i=1;i<n;++i)  
#         if(v[i].a>=dr)   
#             {dr=v[i].b;  ++rez;}   
#       
#     printf("%d\n", rez);   
#     return 0;  
# }  



# int compar (const void*p, const void*q)   
# {     
#     interval *pp=(interval*)p, *qq=(interval*)q;  
#     interval x=*pp, y=*qq;  
#     if(x.b<y.b)  
#         return -1;  
#     if(x.b>y.b)  
#         return 1;  
#     return 0;     
#   
# }  
#   
# int main()  
# {   interval v[N];  
#     int n,dr,i,j,rez=1;  
#     freopen("int.in", "r", stdin);  
#     freopen("int.out", "w",stdout);  
#     scanf("%d", &n);  
#     for(i=0;i<n;i++)  
#         scanf("%d%d", &v[i].a, &v[i].b);  
#     qsort(v,n,sizeof(v[0]),compar);  
#           
#     dr=v[0].b;  
#     for(i=1;i<n;++i)  
#         if(v[i].a>=dr)   
#             {dr=v[i].b;  ++rez;}   
#       
#     printf("%d\n", rez);   
#     return 0;  
# }