4 i.e. 2413. First is 2 as it establishes the SUBJECT i.e. 'The Mayans'.Next is 4 as it is in continuation with 2 and refers to the gods mentioned in 2.After that is 1 as it contextually follows 4.Last is 3 as it refers to the cities mentioned in 1.Correct sequence- The Mayans believed in many gods. They BUILT large TEMPLES to honour these gods. Skilful workers built cities around these temples. However, it was difficult for them to construct these cities.