After 3 hours, it will have 3 * 2 = <<3*2=6>>6 logs added to it.
After 3 hours, it will have burned 3 * 3 = <<3*3=9>>9 logs.
After 3 hours, the cookfire will have 6 + 6 - 9 = <<6+6-9=3>>3 logs left.
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