The Gurmukhī alphabet contains thirty-five base letters ("akkhara", plural "akkharā̃"), traditionally arranged in seven rows of five letters each. The first three letters, or "mātarā vāhak" ("vowel carrier"), are distinct because they form the basis for vowels and are not consonants, or "vianjan", like the remaining letters are, and except for the second letter "aiṛā" are never used on their own; see for further details. The pair of fricatives, or "mūl varag" ("base class"), share the row, which is followed by the next five sets of consonants, with the consonants in each row being homorganic, the rows arranged from the back (velars) to the front (labials) of the mouth, and the letters in the grid arranged by place and manner of articulation. The arrangement, or "varaṇamālā", is completed with the "antim ṭolī", literally "ending group." The names of most of the consonants are based on their reduplicative phonetic values, and the "varaṇamālā" is as follows: