During Codeforces Round 987 (Div. 2), I got Runtime Error on Test Case 59 (in Problem E. Penchick and Chloe's Trees). It shows Stack Overflow Error! But, the same code got AC on C++17 while upsolving!

• C++20 Submission: 291655589 — Runtime Error on TC 59
• C++23 Submission: 291671738 — Runtime Error on TC 61
• C++17 Submission: 291671684 — AC

But, after a little modification on insider loop, it got AC in C++20: 291668944. But, I couldn't find any valid reason for stack-overflow, and how this submission solved this error!

Can you help me?