func gradingStudents(grades []int32) []int32 {
    for i := 0; i<len(grades); i++ {
    switch {
        case grades[i] < 38:
            grades[i] = grades[i]
        case grades[i] % 5 == 3:
            grades[i] = grades [i] + (5-grades[i] % 5)
        case grades[i] % 5 > 3:
            grades[i] = grades [i] + (5-grades[i] % 5)
    }
    }
    return grades
}