ABC125C

C - GCD on Blackboard

• 
• Thoughts.
  • If the remaining gcd after removing one is 1, then it’s 1 no matter what.
    • Because the gcd can never be greater than the argument.
  • In other words, “Find the maximum value of gcd with one removed.”
  • This is obsolete rule prohibiting match-ups between wrestlers from the same group of stables. - Cumulative product from left to right is OK
• Official Explanation
  • Same policy
  • He’s using 0 as a sentry.
  • $\gcd (0,X)=\gcd (X,0)=X$
  • Python standard gcd also behaves this way

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