import sys from math import sin sys.setrecursionlimit(10 ** 7) input = sys.stdin.readline f_inf = float('inf') mod = 10 ** 9 + 7 def resolve(): k = int(input()) res = 0 for i in range(1, 140): res += sin(k * i) / pow(i, i) print(res) if __name__ == '__main__': resolve()