This problem - 📚📚 Read every day challenge - Spring 2022 🌸 🌱 - #281 by polv
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<summary><ruby>Like this?<rt>
[spoiler]かんじ[/spoiler]
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That's right.
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Though, there already exists an easy solution
<details>
<summary><ruby>Like this?<rt><span class="spoiler">かんじ</span></rt></ruby></summary>
That's right.
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Still, think if you want something else more complex…