Eight Russian students volunteered to saw large logs into ½-yard small logs to heat their school. The students were split into pairs, with Pascha, Volodya, Petya and Vasya designated leaders of their respective pairs.

Pascha and Andriy were given 3-yard logs to saw up, Volodya and Misha were given 2-yard logs, Petya and Kostya were given 1½-yard logs and Vasya and Fedya, 1-yard logs. (These are all first names.)

The next day the school bulletin praised the good work of leaders Lavrov, Sukov, Galkin and Medvedev, and their teams. Lavrov’s team produced 36 small logs, Sukov’s team produced 30 logs, Galkin’s produced 20 and Medvedev’s, 24.   (These are all surnames.)

Kostya was a bit miffed that the leaders got all the praise, because he had produced four times as many small logs as his team leader. 

What was Kostya’s leader’s full name?