A and B start from place A at the same time, A walks 7 kilometers every day, B walks 1 kilometer on the first day, 2 kilometers on the second day, 3 kilometers on the third day, and walks 1 kilometer more every day than the previous day ． May I ask how many days the two traveled the same distance?
甲、乙两人同时从A地出发，其中甲每天走7公里，乙第一天走1公里，第二天走2公里，第三天走3公里，以后每天都比前一天多走1公里．请问，二人经过多少天走的路程相同．
<gadget id="calculator">7 * 2</gadget>
<output>14</output>

<gadget id="calculator">14 - 1</gadget>
<output>13</output>

<result>13</result>