Vowel length contrasts with more than two phonemic levels are rare, and several hypothesized cases of three-level vowel length can be analysed without postulating this typologically unusual configuration. Estonian has three distinctive lengths, but the third is suprasegmental, as it has developed from the allophonic variation caused by now-deleted grammatical markers. For example, half-long 'aa' in "saada" comes from the agglutination *"saata+ka" "send+(imperative)", and the overlong 'aa' in "saada" comes from *"saa+ta" "get+(infinitive)". As for languages that have three lengths, independent of vowel quality or syllable structure, these include Dinka, Mixe, Yavapai and Wichita. An example from Mixe is "guava", "spider", "knot". In Dinka the longest vowels are three moras long, and so are best analyzed as overlong etc.