// Phase 104: read_digits_from loop(true) + break-only minimal fixture
// Expect numeric output lines: 2 then 1

static box Main {
  read_digits_min(s, pos) {
    local i = pos
    local out = ""

    loop(true) {
      local ch = s.substring(i, i + 1)

      // end-of-string guard
      if ch == "" { break }

      // digit check (match real-app shape; keep on one line to avoid ASI ambiguity)
      if ch == "0" || ch == "1" || ch == "2" || ch == "3" || ch == "4" || ch == "5" || ch == "6" || ch == "7" || ch == "8" || ch == "9" {
        out = out + ch
        i = i + 1
      } else {
        break
      }
    }

    return out
  }

  main() {
    local a = read_digits_min("12x", 0)
    local b = read_digits_min("9", 0)

    print(a.length())
    print(b.length())
    return "OK"
  }
}