def twoPluses(grid):
    m, n = len(grid), len(grid[0])
    sets = []
    good = {(i,j) for (i,j) in product(range(m), range(n)) if grid[i][j] == "G"}
    for (i, j) in good:
        cur_set = {(i,j)}
        sets.append(cur_set)
        left, right = (i, j - 1), (i, j + 1)
        up, down = (i + 1, j), (i - 1, j)
        while True:
            if left not in good or right not in good:
                break
            if up not in good or down not in good:
                break
            for d in [left, right, up, down]:
                cur_set.add(d)
            sets.append(cur_set.copy())
            left, right = (left[0], left[1] - 1), (right[0], right[1] + 1)
            up, down  = (up[0] + 1, up[1]), (down[0] - 1, down[1])
    
    mx = 0    
    for c1, c2 in product(sets, sets):
        if not c1.intersection(c2):
            sz = len(c1) * len(c2)
            if sz > mx:
                mx = sz
    return mx