void main(){
    int grades[] = {88, 67, 94, 100, 56, 43, 79, 77};
    int count = 0;
    int sum = 0;
    int index = 0;
    int current_grade = 0;
    int high_grade = 0;
    int low_grade = 100;
    float average = 0.0;
    
    /***** Example 1, find highest grade *****/
    
    // loop through all grades
    for(index = 0; index < _array_size(grades); index++){
        // get the current grade
        current_grade = grades[index];
        // test if we found a higher grade
        if( current_grade > high_grade ){
            high_grade = current_grade;
        }
    }
    // display the highest grade
    printf("highest grade is %d\n", high_grade);
    
    
    /***** Example 2, find lowest grade *****/
    
    // loop through all grades
    for(index = 0; index < _array_size(grades); index++){
        // get the current grade
        current_grade = grades[index];
        // test if we found a lower grade
        if( current_grade < low_grade ){
            low_grade = current_grade;
        }
    }
    // display lowest grade
    printf("lowest grade is %d\n", low_grade);
    
    
    /***** Exercise 1, find the sum of all grades *****/
    // Hint: loop through all grades and keep a running total
    
    
    
    // display the sum of all grades
    printf("sum of all grades %d\n", sum);
    
    
    /***** Exercise 2, find the average of all grades *****/
    // Hint: you need the sum from exercise 1
    
    
    
    // display the average grade
    printf("grade average is %f\n", average);
    
    
    /***** Exercise 3, count the number of passing grades (60 or better) *****/
    
    
    
    // display the count of passing grades
    printf("count: %d\n", count);
}