One of the longest-lived animals in the world is the arctic clam, and generally the arctic clam can live to be hundreds of years old. Now there is a big arctic clam, 70 years old this year, and 4 small arctic clams are 3, 4, 5, and 6 years old. After many years, the sum of the ages of the 4 small arctic clams exceeds the age of the big arctic clam for the first time.
世界上最长寿的动物之一就是北极帘蛤，一般北极帘蛤都可以活到几百岁．现在有一只大北极帘蛤，今年70岁，4只小北极帘蛤的年龄分别是3岁、4岁、5岁、6岁．再过多少年，4只小北极帘蛤的年龄之和首次超过大北极帘蛤的年龄．
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