Unable to input two different series of numbers into two different vectors

New learner working through a coding book and having trouble with an exercise problem. The exercise goal was practicing using the for() loop.

I'm trying to read two lines from a .txt file into two different vectors:

Text file:

0 1 1 2
0 1 1 2 3 5 8

Code I've written so far (very likely messy). In the end I couldn't get the vectors to load separately and ended up manually entering the vectors directly into the code, changing the numbers to match or not match, just to make sure I was doing the for() loop near the bottom correctly. I've currently commented out the manual vector entries, because I was trying unsuccessfully to find a solution to my dilemma:

// Exercise 5.17: Given two vectors of ints, write a program to determine whether one vector is a prefix of the other. 
// For vectors of unequal length, compare the number of elements of the smaller vector. 
// For example, given the vectors containing 0, 1, 1, and 2 and 0, 1, 1, 2, 3, 5, 8, respectively your program should return true.

#include <iostream>
#include <vector>
#include <string>

using std::cin;
using std::cout;
using std::endl;
using std::vector;
using std::string;

int main() {

//create two variables to hold vectors 
vector<int> v1 /*{0, 1, 1, 2} */;
vector<int> v2 /*{0, 1, 1, 2, 3, 5, 8} */;

// read from console two lines of numbers into two different vectors

int n{};

// flag to change once a new line is read
bool flag = false;

// input file will only have two lines of only integers
while (cin >> n);{

    if (n == '\n') // when a new line is seen, flip the flag
        flag = true;

        if (!flag) // read the first line of numbers into first vector until you see a new line
            v1.push_back(n);

        else // read the next line of numbers into second vector
            v2.push_back(n);
}

// compare values of the vectors to flag this boolean
bool match = false;

if(v1.size() < v2.size()){ // if v1 is the smaller vector then compare its elements

    for (decltype(v1.size()) index = 0; index != v1.size(); ++index){
        if (v1[index] == v2[index])
            match = true;
        else
            match = false;
    }

}
else {

    for (decltype(v2.size()) index = 0; index != v2.size(); ++index) { // if v2 is the smaller vector then compare its elements
        if (v1[index] == v2[index])
            match = true;
        else
            match = false;
    }

}

// change boolean flag into 'true' or 'false'

string value;

if (match)
    value = "true";
else
    value = "false";

//print out the results

cout << "Do the two vectors match, or is vector 1 a prefix of vector 2: '\n'" << value << endl;

return 0;

}