Three friends who live in the same house leave the house at the same time to go rock climbing on a cliff just outside of town. Anna walks to the cliff and climbs to the top of the cliff. Bob runs to the cliff twice as fast as Anna and walks and climbs the top of the cliff at a rate that is only two-thirds as fast as Anna climbs. Charlie bikes to the cliff at a speed twice as fast as Bob runs and takes two hours longer to climb to the top of the cliff than Anna does. If all three friends reach the top of the cliff at the same time, how many MINUTES after they left home is that?
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