C++ set lower_bound() function

#include<iostream>
#include <bits/stdc++.h>
using namespace std;
int main()
{
   set<int> s;                 //Declaring an empty set container
   set<int>::iterator iter;    //Declaring a set container as iterator which will point to the lower bound value
   s.insert(7);                //inserting elements in the set container s
   s.insert(6);
   s.insert(1);
   s.insert(4);
   s.insert(2);
   s.insert(9);
   s.insert(10);
   iter = s.lower_bound(4);       //passing a key by parameter to find its lower bound
      cout <<"The lower bound of 4 is: "<< *iter << " "<<endl; //printing the lowerbound value
   iter = s.lower_bound(5);
      cout <<"The lower bound of 5 is: " <<*iter << " "<<endl;
   iter = s.lower_bound(30);
      cout <<"The lower bound of 30 is: " <<*iter << " "<<endl;

return 0;
    
}