Bought a lot and then built a house, short term or long term capital gain?

1/31/2020 bought a land for 100k

We started to build a house from early 2021 to mid 2021 with a total cost of $200k

Sold the house on July 2021 for $350k

Is the 50k gain a long term or short term capital gain or mixed? If it is mixed, how to separate them?

Thanks.