local mod = 1000000007LL
local ffi = require("ffi")
local C = ffi.C
ffi.cdef[[
long long atoll(const char*);
]]

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

local a, b = io.read():match("(%d+) (%d+)")
a = lltonumber(a)
b = lltonumber(b)
local ans = false
if a == 0LL then
  ans = (b / 2LL) * 2LL + 1LL
elseif b == 0LL then
  ans = (a / 2LL) * 2LL + 1LL
elseif (a + b) % 2LL == 0LL then
  local x1 = (a - b) / 2LL
  local x2 = (-a - b) / 2LL
  local x3 = (a + b) / 2LL
  local width = x1 - x2 + 1LL
  local height = x3 - x1 + 1LL
  local p = ((width + mod - 1LL) % mod) * ((height + mod - 1LL) % mod)
  p = p % mod
  local q = (width % mod) * (height % mod)
  q = q % mod
  ans = (p + q) % mod
else
  local l1 = a + 1LL
  local l2 = b + 1LL
  local rm = (a % mod) * (b % mod) + ((a + 1LL) % mod) * ((b + 1LL) % mod)
  rm = rm % mod
  local add = ((a * 2LL + 1LL) % mod) * ((b * 2LL + 1LL) % mod)
  ans = (add + mod - rm) % mod
end

ans = tostring(ans % mod):gsub("LL", "")
print(ans)