Three Cannibals...

I know this may sound weird but this is a game we were playing earlier in our lecture.... I you have three normal people and three cannibals on an island. And need to get them all off the island. You have 1 boat that can have two people in it at once. How can you get them all to the mainland? However, the rule is that you cannot have more cannibals than normal people in any place at once. And when they arrive at a shore, everyone has to get off (i.e someone can't just be dropped off, even if one person gets back on the boat to go back). We got 6 bits of paper, 3 with 'C' on and 3 with nothing on. Can anyone figure out how this is possible?