input: [1] Comfortable if traveling in 1st class (SV-type) cabins. Low if traveling in 2nd class cabins. Sub-standard if traveling in 3rd class. [2] Top-notch. Cabins of higher class offer highest level of comfort. Refer to specific luxury train for additional details. [3] Comfortable if traveling in 1st class (SV-type) cabins. Low if traveling in 2nd class cabins. Sub-standard if traveling in 3rd class. [0] 
output: Level of overall comfort