In ABC 141 promblem F, I try to use "ios::sync_with_stdio(false)" with cin & cout, but the the service give me a "WA". after delete it , I get "AC".

Could anyone tell me the reason, Thank you so much.

https://atcoder.jp/contests/abc141/submissions/7850012

https://atcoder.jp/contests/abc141/submissions/7850000