Below is an instruction that describes a task. Write a response that appropriately completes the request in English. Please answer in English.

### Instruction:
Brennan was researching his school project and had to download files from the internet to his computer to use for reference. After downloading 800 files, he deleted 70% of them because they were not helpful. He downloaded 400 more files but again realized that 3/5 of them were irrelevant. How many valuable files was he left with after deleting the unrelated files he downloaded in the second round?

### Response:
The number of non-valuable files Brennan downloaded in the first round is 70/100*800 = <<70/100*800=560>>560
The number of valuable files Brennan downloaded in the first round is 800-560 = <<800-560=240>>240
The number of non-valuable files Brennan downloaded in the second round is 3/5*400 = <<3/5*400=240>>240
The number of valuable files Brennan downloaded in the second round is 400-240 = <<400-240=160>>160
He was left with 160+240 = <<160+240=400>>400 valuable files after deleting the non-valuable files from the second round.
#### 400