A messy girl had 24 socks in the drawer at her bedroom. There are 6 pairs of red socks, 5 pairs of green socks, and 1 pair of blue ones, but all the socks are mixed up. One night she wanted to go out and went to her bedroom for a pair of socks. As she turned on the light, the lamp didn't work, so she had to find her socks in complete darkness.

What's the smallest number of socks she had to take downstairs to be sure to have a matching pair?