What will be the output of the following C++ code?

#include<iostream> 
#include<iterator> 
#include<vector> 
using namespace std; 
int main() 
{ 
    vector<int> ar = { 1, 2, 3, 4, 5 }; 
    vector<int>::iterator ptr = ar.begin(); 
    ptr = advance(ptr, 2);
    cout << *ptr << endl; 
    return 0; 
}