how to access last element of set code example

Example: how to get last element of set

// Example program
#include <iostream>
#include <string>
#include <set>
#include <iterator>
using namespace std;
int main()
{
    set<int>a = {5,9,100,25,4,6};
    auto it = a.end();
    it--;
    cout << *it;
}