instruction: How many of the Lira satellites were successful?
context: Kosmos 1375 was placed into a low Earth orbit with a perigee of 986 kilometres (613 mi), an apogee of 1,003 kilometres (623 mi), 65.8 degrees of inclination, and an orbital period of 105 minutes. On 18 June 1982, it was successfully intercepted and destroyed by Kosmos 1379 in the final Soviet anti-satellite weapons test to be conducted. As of 2022, debris is still in orbit.
  
  Kosmos 1375 was the last of ten Lira satellites to be launched, of which all but the first were successful. Lira was derived from the earlier DS-P1-M satellite, which it replaced.
response: 10 were launched, 1 was not successful, so 10-1 = 9 were successful.