בֶּן־שָׁל֧וֹשׁ וְעֶשְׂרִ֛ים שָׁנָ֖ה יוֹאָחָ֣ז בְּמָלְכ֑וֹ וּשְׁלֹשָׁ֣ה חֳדָשִׁ֔ים מָלַ֖ךְ בִּירוּשָׁלִָֽם׃
Joahaz was twenty and three years old when he began to reign; and he reigned three months in Jerusalem.
Read midrashic interpretation of II Chronicles 36:2: and classical rabbinic exegesis.