$1$ point

Where in this code fragment is the $1$st Hidden Layer of the neural network irisModel specified?

# Build neural network

irisModel $=$ Sequential$()$

irisModel.add$($Dense$(50,$ input$\_$dim$=$irisX.shape$[1],$ activation$=$'relu'$))$

irisModel.add$($Dense$(25,$ activation$=$'relu'$))$

irisModel.add$($Dense$($irisY$.$shape$[1],$ activation$=\text{'}$ softmax' $))$

irisModel.compile$($loss$=$'categorical$\_$crossentropy', optimizer$=$'adam' $)$