N = eval(input())

set1 = "142857"
mod = N%7
dif = N//7

if N == 0:
        print(0)
elif 1 < N < 7:
        tmp = set1[0:N]
        print("0."+tmp)
else:
        tmp = set1
        for it in range(dif-1):
                tmp = tmp + set1
        tmp = tmp + set1[0:mod+1]
        print("0."+tmp)