다음 파이썬 프로그램의 출력 결과는?

student_list = ['A', 'B', 'C', 'D']
student_score = ['92', '85', '77', '54']
student_grade = []
i = 0

for _ in range(len(student_score)):
    try:
        if student_score[_] >= 90:
            student_grade.append('A+')
            i += 1
        elif student_score[_] >= 80:
            student_grade.append('B+')
            i += 1
        elif student_score[_] >= 70:
            student_grade.append('C+')
            i += 1
        else:
            student_grade.append('D+')
            i += 1
    except:
        student_grade.append('F')

print('%s, %s' % (student_list[i], student_grade[i]))