The 35 numbers are arranged in 5 rows and 7 columns. The average numbers of the 7 columns are 39, 41, 40, 45, 42, 39, 41 respectively, and the average numbers of the first 4 rows are 42, 39, 44, 41 respectively. Ask for the average of the last row.
35个数排成5行7列.7列的平均数分别为39、41、40、45、42、39、41，前4行的平均数分别为42、39、44、41．请求出最后一行的平均数．
<gadget id="calculator">39 * 5</gadget>
<output>195</output>

<gadget id="calculator">41 * 5</gadget>
<output>205</output>

<gadget id="calculator">40 * 5</gadget>
<output>200</output>

<gadget id="calculator">45 * 5</gadget>
<output>225</output>

<gadget id="calculator">42 * 5</gadget>
<output>210</output>

<gadget id="calculator">195 + 205 + 200 + 225 + 210 + 195 + 205</gadget>
<output>1_435</output>

<gadget id="calculator">1_435 / 35</gadget>
<output>41</output>

<gadget id="calculator">41 * 35</gadget>
<output>1_435</output>

<gadget id="calculator">42 + 39 + 44 + 41</gadget>
<output>166</output>

<gadget id="calculator">166 * 7</gadget>
<output>1_162</output>

<gadget id="calculator">1_435 - 1_162</gadget>
<output>273</output>

<gadget id="calculator">273 / 7</gadget>
<output>39</output>

<result>39</result>