In Classical Greek numerals, a myriad was written as a capital mu: Μ, as lower case letters did not exist in Ancient Greece. To distinguish this numeral from letters, it was sometimes given an overbar: . Multiples were written above this sign, so that for example would equal 4,582×10,000 or 45,820,000. The etymology of the word "myriad" itself is uncertain: it has been variously connected to PIE "*meu-" ("damp") in reference to the waves of the sea and to Greek "myrmex" (, "ant") in reference to their swarms.