1 (one;  /ˈwʌn/ or UK /ˈwɒn/) is a number, a numeral, and the name of the glyph representing that number. It represents a single entity, the unit of counting or measurement. For example, a line segment of "unit length" is a line segment of length 1.

One, sometimes referred to as unity, is the integer before two and after zero. One is the first non-zero number in the natural numbers as well as the first odd number in the natural numbers.

Any number multiplied by one is the number, as one is the identity for multiplication. As a result, one is its own factorial, its own square, its own cube, and so on. One is also the empty product, as any number multiplied by one is itself, which produces the same result as multiplying by no numbers at all.

The glyph used today in the Western world to represent the number 1, a vertical line, often with a serif at the top and sometimes a short horizontal line at the bottom, traces its roots back to the Indians, who wrote 1 as a horizontal line, much like the Chinese character 一. The Gupta wrote it as a curved line, and the Nagari sometimes added a small circle on the left (rotated a quarter turn to the right, this 9-look-alike became the present day numeral 1 in the Gujarati and Punjabi scripts). The Nepali also rotated it to the right but kept the circle small. This eventually became the top serif in the modern numeral, but the occasional short horizontal line at the bottom probably originates from similarity with the Roman numeral Failed to parse (Missing texvc executable; please see math/README to configure.): \mathrm{I} . In some European countries (e.g., Germany), the little serif at the top is sometimes extended into a long upstroke, sometimes as long as the vertical line, which can lead to confusion with the glyph for seven in other countries. Where the 1 is written with a long upstroke, the number 7 has a horizontal stroke through the vertical line.

A number is a mathematical object used to count and measure. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers.

Mathematical operations are certain procedures that take one or more numbers as input and produce a number as output. Unary operations take a single input number and produce a single output number. For example, the successor operation adds one to an integer, thus the successor of 4 is 5. Binary operations take two input numbers and produce a single output number. Examples of binary operations include addition, subtraction, multiplication, division, and exponentiation. The study of numerical operations is called arithmetic.

A notational symbol that represents a number is called a numeral. In addition to their use in counting and measuring, numerals are often used for labels (telephone numbers), for ordering (serial numbers), and for codes (e.g., ISBNs).

DJ Wich (also known as Tomáš Pechlák) is a DJ who works the Czech/Slovkia hip-hop scene. He started DJing in 1998.

In 1993, DJ Wich met Indy and LA4 on a graffiti scene. In 1998 they formed Indy & Wich, where Indy performed as a rapper and DJ Wich as producer. They often work with rapper LA4 in live performances.

In 2002, they released their debut album My3. Their second album Hádej kdo… was nominated on Anděl in 2006. The following year they produced The Chronicles of Nomad with rapper Nironic.

In 2008, DJ Wich released his first solo album The Golden Touch with international stars like Lil Wayne, Talib Kweli, M.O.P, Kurupt and more.

He collaborated with Czech artists, including Orion, Hugo Toxxx, W518, LA4 and from the international Rasco, Rytmus, H16, Vec, and Nironic.

Wich streams live shows from (DJ Wich Live TV) with other rappers, live recording, interviews and chat.

DJ Wich made soundtracks for Czech movie Gympl and Ulovit miliardáře which was released on 1 October 2008 with Tomáš Vorel as director.