educative.io

Type Coercion. Incorrect solution

What will this code print?

    let str = 'Hello';
    let bool = 0;
    console.log(str - bool);

I have run this on my system and the correct answer is: Hello0

However, on educative.io it shows the answer is: NaN

Javascript changes the type of number 0 to string ‘0’, and therefore, the correct answer is: Hello0

Kindly correct this on the website.