Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
Which tonnage has a Date of 26 september 1940, and a Ship Name of ashantian?

### Inputs:
table_name: table, columns: ['Date', 'Ship Name', 'Flag', 'Tonnage ( GRT )', 'Fate', 'Deaths']

### Response:
SELECT MIN Tonnage ( GRT ) FROM table WHERE Date = 26 september 1940 AND Ship Name = ashantian