n = int(input())
if n < 10:
    print('%.1f' % (n * 1.5))
if n >= 10:
    print('%.1f' % (n * 1.2))

/**************************************************************
	Problem: 1630
	User: admin
	Language: Python
	Result: Accepted
	Time:135 ms
	Memory:34244 kb
****************************************************************/