C++ quiz. For given vector iterators. Does this code compile

For given vector iterators. Does this code compile? If it fails, please choose the lines on which it does.

vector<int> vec(3,1);
const std::vector<int>::iterator iter = vec.begin();
*iter = 10; //1
++iter;      //2
std::vector<int>::const_iterator iter2 = vec.begin();
*iter2 = 10;//3
++iter2;     //4

Compilation error on line 1
Compilation error on line 2
Compilation error on line 3
Compilation error on line 4
Code will compile successfully

Explanation

const_iterator don't allow you to change the values that they point to ( std::vector::const_iterator )
const std::vector::iterator - iterator isn’t allowed to point to something different, but the thing it points to may be modified.