record R {
  start = 0
}
state ranges: list of R
state t = 0
input go = message { n: u32 }
on go {
  if ranges.count == 0 {
    for i in 0 .. 1000 { ranges.append(R { start: i }) }
  }
  let s = 0
  for i in 0 .. go.n { s = s + ranges[i].start }
  t = s
}