C++ :: How To Insert Try / Catch Throw

I have this code I wrote with some data and what I'm supposed to do is insert exception handling into the code. The problem is I've seen the basic examples of it. But I don't know how to implement it into my code.

#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
using namespace std;
int main(){
string filename, n;
cout << "To find a file, type in the file name. " <<endl;

[Code] .....

And the file is:
A
F
D
E
U
B
V
X
M
V