elif

Nested conditions can get pretty deep very quickly. That makes reading the code difficult and programmers tend to avoid having many nested conditions (and having too much-nested code in general). Python provides a utility elif that helps in avoiding else and then if statements:

if name == 'Alice':
    print('Hey there!')
else:
    if name == 'Bob':
        print('How are you doing?')
    else:
        if name == 'Anna':
            print('Hello, Anna')
        else:
            print('Hi!')

if name == 'Alice':
    print('Hey there!')
elif name == 'Bob':
    print('How are you doing?')
elif name == 'Anna':
    print('Hello, Anna')
else:
    print('Hi!')

These two programs do exactly the same. They print personalized greeting messages and contain many if/else statements. Yet, the first one has many layers of nested if/else blocks, while the second uses elif statements which stands for else if.

Challenge

Having a grade which is a number from 0 to 100, we would like to know what would that grade correspond to in the US Letter grading system (A, B, C, D, and F).

Note: Do not use only if statements with range checks. Use elif when checking for another condition.

Write a program that would do the conversion.