solve in c language

Q.1 Consider the following situation - In a building there can be N number of floors, to reach on a particular floor we just have a staircase. if the floor number is even then there would be 10*2+no of floor steps in a staircase, if the floor number is odd then there would be 10*2+10+1 steps. Only floor number 6 is such a floor which has 22 steps. If the building has 12 floors, write a program that would help you to find out how many steps would be required to reach any floor. Sample Input 1:25 Sample Input 2:- 10 Sample Output 1:- 139 Sample Output 2:- 281||