#MLE注意！0や1のケースに注意



def main():

    import sys

    input = sys.stdin.readline

    sys.setrecursionlimit(10**7)

    from collections import Counter, deque

    #from collections import defaultdict

    from itertools import combinations, permutations, accumulate, groupby, product

    from bisect import bisect_left,bisect_right

    from heapq import heapify, heappop, heappush

    import math

    from math import gcd



    #inf = 10**17

    #mod = 10**9 + 7



    x = int(eval(input()))

    n = 100

    res = 0

    while n < x:

        res += 1

        n = int(n*1.01)

    print(res)



if __name__ == '__main__':

    main()
#MLE注意！0や1のケースに注意



def main():

    import sys

    input = sys.stdin.readline

    sys.setrecursionlimit(10**7)

    from collections import Counter, deque

    #from collections import defaultdict

    from itertools import combinations, permutations, accumulate, groupby, product

    from bisect import bisect_left,bisect_right

    from heapq import heapify, heappop, heappush

    import math

    from math import gcd



    #inf = 10**17

    #mod = 10**9 + 7



    x = int(eval(input()))

    n = 100

    res = 0

    while n < x:

        res += 1

        n = n*101//100

    print(res)



if __name__ == '__main__':

    main()

# MLE注意！0や1のケースに注意
def main():
    import sys

    input = sys.stdin.readline
    sys.setrecursionlimit(10**7)
    from collections import Counter, deque

    # from collections import defaultdict
    from itertools import combinations, permutations, accumulate, groupby, product
    from bisect import bisect_left, bisect_right
    from heapq import heapify, heappop, heappush
    import math
    from math import gcd

    # inf = 10**17
    # mod = 10**9 + 7
    x = int(eval(input()))
    n = 100
    res = 0
    while n < x:
        res += 1
        n = int(n * 1.01)
    print(res)


if __name__ == "__main__":
    main()

# MLE注意！0や1のケースに注意
def main():
    import sys

    input = sys.stdin.readline
    sys.setrecursionlimit(10**7)
    from collections import Counter, deque

    # from collections import defaultdict
    from itertools import combinations, permutations, accumulate, groupby, product
    from bisect import bisect_left, bisect_right
    from heapq import heapify, heappop, heappush
    import math
    from math import gcd

    # inf = 10**17
    # mod = 10**9 + 7
    x = int(eval(input()))
    n = 100
    res = 0
    while n < x:
        res += 1
        n = n * 101 // 100
    print(res)


if __name__ == "__main__":
    main()

-        n = int(n * 1.01) +        n = n * 101 // 100