from Queue import * # Queue, LifoQueue, PriorityQueue
from bisect import * #bisect, insort
from collections import * #deque, Counter,OrderedDict,defaultdict
#set([]) 
import math
import copy
import itertools
import string
import sys
myread = lambda : map(int,raw_input().split())
def solver():
    D = int(raw_input())
    D = str(D * 108)
    print D[:-2] + "." + D[-2:]
if __name__ == "__main__":
    solver()