local function lltonumber(str)
  local ret = 0LL
  local sign = str:sub(1, 1) ~= "-"
  local begin = sign and 1 or 2
  for i = begin, #str do
    ret = ret * 10LL + str:sub(i, i):byte() - 48
  end
  if not sign then ret = ret * -1LL end
  return ret
end

local a = {}
for i = 1, 5 do
  a[i] = lltonumber(io.read())
end

local fib = {1LL, 1LL}
while true do
  local nxt = fib[#fib] + fib[#fib - 1]
  if 10^15 < nxt then break end
  table.insert(fib, nxt)
end
local ret = 0
for i = 1, #fib do
  local c = 0
  for j = 5, 1, -1 do
    if fib[i + 5 - j] == a[j] then
      c = c + 1
    else
      break
    end
  end
  ret = ret < c and c or ret
end
print(ret)