There was a man who went to the mall and he bought 3 pairs of red socks and 3 pairs of white socks. Another man who already bought 3 pairs of red socks and 3 pairs of white socks came back to return his 3 pairs of red socks and 3 pairs of white socks. They are both blind. As they were walking they bumped into each other. All the socks scattered around the floor, but each pair remained held together by a rubber band. Nobody helped them pick it up except each other, but in 3 minutes they both put them back altogether. Each man ended up with the same colors of socks he started with: six red and six white.

How is that possible if they are blind?