import sys



readline = sys.stdin.readline

MOD = 10 ** 9 + 7

INF = float('INF')

sys.setrecursionlimit(10 ** 5)





def main():

    x = int(eval(input()))



    year = 0

    money = 100



    while money < x:

        money *= 1.01

        money = int(money)

        year += 1



    print(year)





if __name__ == '__main__':

    main()

import sys



readline = sys.stdin.readline

MOD = 10 ** 9 + 7

INF = float('INF')

sys.setrecursionlimit(10 ** 5)





def main():

    x = int(eval(input()))



    year = 0

    money = 100

    

    from math import floor

    

    while money < x:

        money *= 1.01

        money = floor(money)

        year += 1



    print(year)





if __name__ == '__main__':

    main()

import sys

readline = sys.stdin.readline
MOD = 10**9 + 7
INF = float("INF")
sys.setrecursionlimit(10**5)


def main():
    x = int(eval(input()))
    year = 0
    money = 100
    while money < x:
        money *= 1.01
        money = int(money)
        year += 1
    print(year)


if __name__ == "__main__":
    main()

import sys

readline = sys.stdin.readline
MOD = 10**9 + 7
INF = float("INF")
sys.setrecursionlimit(10**5)


def main():
    x = int(eval(input()))
    year = 0
    money = 100
    from math import floor

    while money < x:
        money *= 1.01
        money = floor(money)
        year += 1
    print(year)


if __name__ == "__main__":
    main()

+    from math import floor + -        money = int(money) +        money = floor(money)