local mfl = math.floor

local function comp(a, b)
  return a < b
end

local function lower_bound(ary, x)
  local num = #ary
  if num == 0 then return 1 end
  if not comp(ary[1], x) then return 1 end
  if comp(ary[num], x) then return num + 1 end
  local min, max = 1, num
  while 1 < max - min do
    local mid = mfl((min + max) / 2)
    if comp(ary[mid], x) then
      min = mid
    else
      max = mid
    end
  end
  return max
end

local n, m = io.read("*n", "*n")
local l = {}
for i = 1, n do
  l[i] = io.read("*n")
end
local ans = 0
for i = 1, m do
  local f, b, w = io.read("*n", "*n", "*n")
  local lb = lower_bound(l, f)
  local len = 0
  if lb == 1 then
    len = l[1] - f
  elseif n < lb then
    len = f - l[n]
  else
    len = math.min(l[lb] - f, f - l[lb - 1])
  end
  ans = ans + math.max(b, w - len)
end
ans = tostring(ans * 1LL):gsub("LL", "")
print(ans)