34. The construction cost of a project must not exceed 2.3 million yuan. If the project is undertaken by Company A, it will take 18 days, with a daily fee of 150,000 yuan; if undertaken by Company B, it will take 27 days, with a daily fee of 80,000 yuan. To shorten the construction period, it is decided that Company A will work for $m$ days, and the remaining work will be completed by Company B. Then, when $m=$ $\qquad$, the total construction period is the shortest.
Answer: 4