COSH, as a substituent; each of RMC1 and RMC2 which are independent of each other, is a hydrogen atom, an alkyl group which may be substituted, or an alkenyl group which may be substituted; YMC represents the following group: YMC1 represents a bivalent organic connecting group, cMC is 0 or 1, and YMC2 is a carbonyl group or a group represented by the following formula {circle over (1)}, {circle ov