
This letter is just like the English M, except that the lower-case version is identical to the upper-case version: Мм. It also looks different in handwriting: it begins unconnected at the bottom and has just two peaks: Мм.
Mayakovsky, full name Vladimir Vladimirovich Mayakovsky/Владимир Владимирович Маяковский, (1893-1930) was a preeminent poet of the Soviet Futurist movement. My cousin Kolya is a big fan of him, but I don't quite understand him myself.