Trinairo

Trinairo is a logic puzzle. Enter a letter in each cell so that each letter appears the same number of times in each row and column.

Rules: In each cell of the grid, you must enter one of the letters A, B, or C. Each letter should appear the same number of times in each row and column.
Letters in the orthogonal neighbouring cells of a grey cell must be different from the letter in that grey cell.