def getLetterGrade(score):
    """
    Method to return the letter grade schollar of a student.
    :param score: A integer with the final grade schollar of a student.
    :return: return the final letter grade schollar.
    """
    if score >= 90:
        finalScore = 'A'
    elif score >= 80:
        finalScore = 'B'
    elif score >= 70:
        finalScore = 'C'
    elif score >= 60:
        finalScore = 'D'
    else:
        finalScore = 'F'
    return finalScore