Two runners are competing in a 10-mile race.  The first runs at an average pace of 8 minutes per mile, while the second runs at an average pace of 7 minutes per mile.  After 56 minutes, the second runner stops for a drink of water.  For how many minutes could the second runner remain stopped before the first runner catches up with him?
Please reason step by step, and put your final answer within \boxed{}.
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