Convert from firkin [butter, soap] to centner [Russia]

Unit Definition (firkin [butter, soap])
The firkin [butter, soap] is a traditional unit of weight for butter and soap, equal to 4 stone or 56 pounds (about 25.40 kilograms).

Unit Definition (centner [Russia])
The centner [Russia] is a Russian weight or mass unit equal to 100 kilograms (approximately 220.4623 pounds). This centner, also used in Ukraine and the other former Soviet republics, is equal to the decitonne and to the metric quintal; it is twice the size of the centner [Germany] used in western Europe.