Japanese former residents of a group of Russian-controlled islands off Hokkaido flew to two of the disputed isles Saturday to visit their ancestors’ graves, in the first such
air trip negotiated during a decades-long territorial spat.
S (Japanese) former residents
→ [of] a group
→ [of] Russian-controlled islands
[to] two [of] the disputed isles
V [to visit]
O (their ancestors’) graves
, [in] the first such air trip 初めての飛行旅行
→ negotiated 交渉
[during] a decades-long territorial spat.