import cmath
import math
from fractions import Fraction

N = int(input())

M = 1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9

val = 0
for k in range(M):
    num = cmath.exp(2 * k * N * math.pi * 1j / M)
    dnm = cmath.exp(4 * k * math.pi * 1j / M)
    dnm += cmath.exp(2 * k * math.pi * 1j / M)
    dnm += 10
    val += num / dnm
val /= M
# print(val)

x = Fraction(val.real)
y = x.limit_denominator(10**(-N+1))
# print(y)

y_num = y.numerator
y_dnm = y.denominator

tmp = y_dnm

c2 = 0
c5 = 0

while tmp % 2 == 0:
    c2 += 1
    tmp //= 2
while tmp % 5 == 0:
    c5 += 1
    tmp //= 5
# print(c2, c5, tmp)

if c2 > c5:
    y_num *= 5**(c2-c5)
    y_dnm *= 5**(c2-c5)
elif c2 < c5:
    y_num *= 2**(c5-c2)
    y_dnm *= 2**(c5-c2)

print(y_num, y_dnm, sep='/')