What is the smallest ROM size of any phone made by company Nokia?
SELECT T1.ROM_MiB FROM chip_model AS T1 JOIN phone AS T2 ON T1.Model_name   =   T2.chip_model WHERE T2.Company_name  =  "Nokia Corporation" order by T1.ROM_MiB limit 1
smallest ROM size refers to MIN(ROM_MiB); phone made by company Nokia refers to WHERE Company_name = 'Nokia Corporation';