台Taivo A Taiwan Mandarin dictionary

不約而同

bùyuēértóng

ㄅㄨˋ ㄩㄝㄦˊ ㄊㄨㄥˊ

Simplified 不约而同

1(idiom) (of two or more people) to take the same action without prior consultation; (usu. used adverbially) all (or both) of them, independently; as if by prior agreement

Keep 不約而同 and it comes back until you know it.