Nishimura's force consisted of two battleships, one cruiser and four destroyers. Because they were observing radio silence, Nishimura was unable to synchronize with Shima and Kurita. Nishimura and Shima had failed to even coordinate their plans before the attacks – they were long-time rivals and neither wished to have anything to do with the other. When he entered the narrow Surigao Strait at about 02:00, Shima was 22 miles (40 km) behind him, and Kurita was still in the Sibuyan Sea, several hours from the beaches at Leyte. As they passed Panaon Island, Nishimura's force ran into a trap set for them by the U.S.-Australian 7th Fleet Support Force. R. Adm. Jesse Oldendorf had six battleships, four heavy cruisers, four light cruisers, 29 destroyers and 39 PT boats. To pass the strait and reach the landings, Nishimura had to run the gauntlet. At about 03:00 the Japanese battleship Fusō and three destroyers were hit by torpedoes and Fusō broke in two. At 03:50 the U.S. battleships opened fire. Radar fire control meant they could hit targets from a much greater distance than the Japanese. The battleship Yamashiro, a cruiser and a destroyer were crippled by 16-inch (406 mm) shells; Yamashiro sank at 04:19. Only one of Nishimura's force of seven ships survived the engagement. At 04:25 Shima's force of two cruisers and eight destroyers reached the battle. Seeing Fusō and believing her to be the wrecks of two battleships, Shima ordered a retreat, ending the last battleship-vs-battleship action in history.
Try to answer this question if possible (otherwise reply "unanswerable"): How many miles was Shima's fleet behind Nishimura?
22