Problem G
Elevators
                                                                                    
  Whenever a new building is built, it must comply with all the relevant building regulations. In particular, there are rules governing the number of elevators a building must have depending on its number of floors and zoning district.
If a building has only one floor, it doesn’t need any elevators; otherwise, it needs more elevators the more floors it has, and the exact number depends on its zoning district. The following tables describe the number of elevators necessary for a building in each of the residential, commercial, and industrial zoning districts.
| 
               Residential  | 
            
               Commercial  | 
            
               Industrial  | 
          |||
| 
               Floors  | 
            
               Elevators  | 
            
               Floors  | 
            
               Elevators  | 
            
               Floors  | 
            
               Elevators  | 
          
| 
               $1$  | 
            
               $0$  | 
            
               $1$  | 
            
               $0$  | 
            
               $1$  | 
            
               $0$  | 
          
| 
               $2-5$  | 
            
               $1$  | 
            
               $2-7$  | 
            
               $1$  | 
            
               $2-4$  | 
            
               $1$  | 
          
| 
               $6-10$  | 
            
               $2$  | 
            
               $8-14$  | 
            
               $2$  | 
            
               $5-8$  | 
            
               $2$  | 
          
| 
               $11-15$  | 
            
               $3$  | 
            
               $15-20$  | 
            
               $3$  | 
            
               $9-12$  | 
            
               $3$  | 
          
| 
               $16-20$  | 
            
               $4$  | 
            
               $13-16$  | 
            
               $4$  | 
          ||
| 
               $17-20$  | 
            
               $5$  | 
          ||||
You are given the zoning district of a new building and how many floors it has. How many elevators does it need?
Input
The only line of input contains a string representing the zoning district of the building (“residential”, “commercial”, or “industrial”), followed by a space and an integer $N$ ($1 \leq N \leq 20$), the number of floors the building has.
Output
Output a single integer: the number of elevators the building must have.
| Sample Input 1 | Sample Output 1 | 
|---|---|
          residential 6  | 
        
          2  | 
      
| Sample Input 2 | Sample Output 2 | 
|---|---|
          industrial 20  | 
        
          5  | 
      
