After many years, two friends met. In the discussion, it was found out that both of them were married and in the water. The first friend asked the second friend the number of his children and he replied that the sum of their ages was 13. When he asked for some more information to find out the age of each, he said that the product of their ages is equal to the number of windows in the building next to them. The first friend asked for some more information and the second friend said that if the younger son has blue eyes. Then the first friend was able to find out the age of each of his children. Find out their ages by mathematical analysis.

[translated by google translate]