You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Serbo-Croatian

Context:
Like other South Slavic languages, Serbo-Croatian has a simple phonology, with the common five-vowel system and twenty-five consonants. Its grammar evolved from Common Slavic, with complex inflection, preserving seven grammatical cases in nouns, pronouns, and adjectives. Verbs exhibit imperfective or perfective aspect, with a moderately complex tense system. Serbo-Croatian is a pro-drop language with flexible word order, subject–verb–object being the default. It can be written in Serbian Cyrillic or Gaj's Latin alphabet, whose thirty letters mutually map one-to-one, and the orthography is highly phonemic in all standards.

Question:
How many vowels does the Serbo-Croatian language have?

five