write two inputs to interpreted MATLAB block

I have a problem: I have entered data to the interpreted Matlab Fcn block, however the script only manages to write the first data, the first variable ('a'), how could I get the writing of the other data ('b'). I attach images.

Answer 1

[Fangjun Jiang]

Specify as "mod1(u(1),u(2))". Look at the Help of the block.