I am trying to implement Koppen's Climate classification on my map based on the amount of precipitation and temperature in US. The following is the criteria for B climate zones.
"70% or more of annual precipitation falls in the summer half of the year and r less than 20t + 280, or 70% or more of annual precipitation falls in the winter half of the year and r less than 20t, or neither half of the year has 70% or more of annual precipitation and r less than 20t + 140"
What I did was that I used a modelbuilder to calculate r less than 20t + 280, r less than 20t, and r less than 20t + 140, and then I tried to use Con tool to assign each one of these 3 if certain condition is true (70% or more of annual precipitation falls in the summer half of the year, 70% or more of annual precipitation falls in the winter half of the year , and else).
The picture below is my model. The one in the middle is where I did the calculation of 3 different values, and the one on the left if my Con expression for summer and the left one is my con expression for winter.
How can I do the "else" in Con tool? 
