local mfl = math.floor

local function llprint(llnumber)
  --usage: llprint(2 * 1234567890123456LL)
  local str = tostring(llnumber):gsub("LL", "")
  print(str)
end

local ffi = require("ffi")
local C = ffi.C
ffi.cdef[[
long long atoll(const char*);
]]

local function lltonumber(str)
  return C.atoll(str)
end

x = io.read()
x = lltonumber(x)
a = 100LL
cnt = 0
while a < x do
  a = a + a / 100LL
  cnt = cnt + 1
end
print(cnt)
