Seym

The Seym (also spelled Seim and Sejm) is a river in Russia and Ukraine that flows west. It has a length of 748 kilometers (465 miles) (250 kilometers within Ukraine) and a basin area of approximately 27,500 square kilometers (10,600 sq mi). It is Desna's main tributary. The Desna is a major left-tributary of the Dnieper River in Russia and Ukraine. In the Old East Slavic language, its name means "right hand." It is 1,130 km (702 mi) long and has a drainage basin area of 88,900 km2 (34,324 sq mi). The river's width in Ukraine ranges from 60 to 250 meters (200 to 820 feet), with an average depth of 3 meters (10 ft). At its mouth, the average annual discharge is 360 m3/s (13,000 cu ft/s).

Kursk, Kurchatov, Rylsk, Ukrainian border, Putyvl, Baturin, junction with Desna, which flows west and south past Chernihiv to Kyiv.

Length: 748 km (465 mi- shared with Russia)