wtf, rev.1

#!/usr/bin/env ruby
n = STDIN.readline().strip().to_i()
numbers = STDIN.readline().split(/\s/).compact().map(&:to_i)
answer = STDIN.readline().strip().to_i()

if (numbers.length != n) then
  printf("array size mismatch\n")
  exit
end

def exit_no_solution()
  printf("no solution\n")
  exit
end

min = numbers[0]
i = 1; while (i < n) do
  min -= numbers[i]
  i += 1 ## it's better to use "i++", but Ruby doesn't have increment
end
if (answer < min) then
  exit_no_solution()
end

max = 0
i = 0; while i < n do
  max += numbers[i]
  i += 1 ## it's better to use "i++", but Ruby doesn't have increment
end

if (answer > max) then
  exit_no_solution()
end

## array with signs: "false" means "-", "true" means "+" %)
signs = Array.new(n, false) ### [false, false, false, ...]
signs[0] = true ### [true, false, false, ...]

while true do
  result = 0
  i = 0; while i < n do
    if signs[i] then
      result += numbers[i]
    else
      result -= numbers[i]
    end
    i += 1 ## it's better to use "i++", but Ruby doesn't have increment
  end

  if result == answer then
    printf("%d = ", answer)
    i = 0; while i < n do
      if (i != 0) then
        if signs[i] then
          printf(" + ")
        else
          printf(" - ")
        end
      end
      printf("%d", numbers[i])
      i += 1 ## it's better to use "i++", but Ruby doesn't have increment
    end
    printf("\n")
    exit
  end

  ## treat signs as little-endian binary value and implement increment logic on top of it
  ## k - index of last "false" element
  k = n; while k != 0 do
    k -= 1 ## it's better to use "k--", but Ruby doesn't have decrement
    if ! signs[k] then
      break
    end
  end

  ## if k points to first element then our "little-endian value" has reached maximum value
  ## nothing to do here, sorry
  if k == 0 then
    break
  end

  ## increment element
  signs[k] = true

  ## decrement elements after current
  i = k + 1; while i < n do
    signs[i] = false
    i += 1 ## it's better to use "i++", but Ruby doesn't have increment
  end

  ## proceed to next iteration
end

exit_no_solution()