#k = int(input())

#s = input()

#a, b = map(int, input().split())

#l = list(map(int, input().split()))



x = int(eval(input()))



yokin = 100



for i in range(1, 100000000000):

    yokin *= 101

    yokin = yokin //100

    if (yokin >= x):

        print(i)

        break

#k = int(input())

#s = input()

#a, b = map(int, input().split())

#l = list(map(int, input().split()))



x = int(eval(input()))



yokin = 100



for i in range(1, 100000000000):

    yokin += yokin // 100

    if (yokin >= x):

        print(i)

        break

# k = int(input())
# s = input()
# a, b = map(int, input().split())
# l = list(map(int, input().split()))
x = int(eval(input()))
yokin = 100
for i in range(1, 100000000000):
    yokin *= 101
    yokin = yokin // 100
    if yokin >= x:
        print(i)
        break

# k = int(input())
# s = input()
# a, b = map(int, input().split())
# l = list(map(int, input().split()))
x = int(eval(input()))
yokin = 100
for i in range(1, 100000000000):
    yokin += yokin // 100
    if yokin >= x:
        print(i)
        break

-    yokin *= 101 -    yokin = yokin // 100 +    yokin += yokin // 100