helping

#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

string fullName;

double grade, age;

string inputFullName()
{
    cout << " Enter your full name: ";

    getline(cin >> ws, fullName);

    if (fullName.size() < 2)
    {
        cout << "\n";

        cout << " Your name should contain at least 2 letters!" << "\n" << "\n";

        return inputFullName();
    }

    return fullName;
}

int inputGrade()
{
    cout << " Enter a grade: ";
    cin >> grade;

    if (grade < 2 && grade > 6)
    {
        return inputGrade();
    }

    return grade;
}

int inputAge()
{
    cout << " Enter your age: ";
    cin >> age;

    if (age < 0)
    {
        return inputAge();
    }

    return age;
}

int gradeInt()
{
    cout << setiosflags(ios::fixed) << setprecision(2);

    grade = round(grade);

    int gradeInt = grade;

    return gradeInt;
}

int ageInt()
{
    cout << setiosflags(ios::fixed) << setprecision(2);

    age = round(age);

    int ageInt = age;

    return ageInt;
}

int main()
{
    inputFullName();

    cout << "\n";

    inputAge();

    cout << "\n";

    inputGrade();

    cout << "\n \n \n";

    cout << " Name: " << fullName << "\n";

    cout << " Age: " << ageInt() << "\n";

    cout << " Grade: " << gradeInt() << "\n";

    cout << "\n" << "\n";

    string repeat;

    cout << " If you want to repeat, type one of these: YES, Yes/yes, Y/y." << "\n";
    cout << " If not, type: NO, No/no, N/n." << "\n" << "\n";

    cout << " Your answer is: ";

    cin >> repeat;

    for (int i = 0; i < repeat.length(); i++)
    {
        repeat[i] = tolower(repeat[i]);
    }

    if (repeat == "yes" || repeat == "y")
    {
        cout << "\n" << "\n";

        main();
    }

    else if (repeat == "no" || repeat == "n")
    {
        return 0;
    }

    return 0;
}