def main():

    x = int(eval(input()))

    m = 100

    for i in range(10**5):

        if m >= x:

            print(i)

            return

        m += m//100



if __name__ == "__main__":

    main()
def main():

    x = int(eval(input()))

    money = 100

    for i in range(10**5):

        if money >= x:

            print(i)

            return

        money += money//100





if __name__ == "__main__":

    main()

def main():
    x = int(eval(input()))
    m = 100
    for i in range(10**5):
        if m >= x:
            print(i)
            return
        m += m // 100


if __name__ == "__main__":
    main()

def main():
    x = int(eval(input()))
    money = 100
    for i in range(10**5):
        if money >= x:
            print(i)
            return
        money += money // 100


if __name__ == "__main__":
    main()

-    m = 100 +    money = 100 -        if m >= x: +        if money >= x: -        m += m // 100 +        money += money // 100