2 blindmen bought black and white socks in a socks shop, each having 5 pairs of black socks and 5 pairs of white socks. But, they fall on the ground when they leave the shop at the front door. All 10 pairs of black socks and 10 pairs of white socks mixed on the ground. Then they sit on the ground and discusse what to do. Each of them brings back home exactly 5 pairs of black socks and 5 pairs of white socks after a couple of minutes. How do they manage to get the correct socks? (Note: Both of them have a guiding dog but neither of the dogs has been trained to sort socks by colors.)