Long term capital gain tax calculation

Hi,

Kindly confirm what would be the LTCG tax in the below scenario.

Amount invested : 10 Lacs

Date of investment: 4 lump sum investments in  2018 in different months. 

Holding period : 5 years

Value of MF units after 5 years : 20 Lacs (10 Lac invested + 10 Lac Gain)

Redemption/Sale Amount : 10 Lacs

What will be the tax in this scenario?

My understanding is since sale amount and purchase amount are same the LTCG tax is nil. 

Is my understanding correct?.