Each cell of a 23×23 grid is colored green, red, or blue. Luke starts at the top-right cell of the grid and walks to the bottom-left cell either by moving one cell to the left, or one cell down. So, he goes through exactly 45 cells on his walk (including the top-right and bottom-left cells). Find the number of colourings in which Luke is guaranteed to pass through exactly 7 red cells, exactly 19 green cells, and exactly 19 blue cells no matter which path he travels on. Submit your answer modulo $10^9+7$