GREATEST VALUE SCRIPT CALL

Is there any script call function or similar workaround to determine the greatest value of four integers, then use that value for further use? Actually, right now I only need to determine if the final value is positive or negative. Final script along the lines of:

If (greatvar(v,v,v,v)) <=0; string
Else; string

I am using rand(max) to get stored variables 1,2,3,4; so if I could determine it from their values instead of storing variables it would be better.