most commonly spelled "1Я" it can be used as a letter, number and pronoun. As a number anything plus, minus, divided by, multiplied by, square route of, etc. equals infinity. With the exception of 1Я being used twice. then it equals 2 infinities. As a letter its silent. Except when it replaces the "ch" sound. It can replace ANY pronoun at ANY time.
"Sometimes i like to say hello to my friend 1Яarles"
"1Я wanna talk to 1Я about 1Я stick"
"Stop Right There! It's 1Я not 'Rteen'."