Abandoned warehouse

from collections import deque

def abandoned_warehouse():
    n, m = map(int, input().split())
    grid = []
    start = None
    end = None
    
    for i in range(n):
        row = input().strip()
        grid.append(row)
        for j in range(m):
            if row[j] == 'A':
                start = (j, i)
            elif row[j] == 'B':
                end = (j, i)

    directions = [(0, -1, 'U'), (0, 1, 'D'), (-1, 0, 'L'), (1, 0, 'R')]
    queue = deque([(start[0], start[1], "")])
    visited = set()
    visited.add(start)
    
    while queue:
        x, y, path = queue.popleft()
        if (x, y) == end:
            print(f"YES\n{len(path)}\n{path}")
            return
        for dx, dy, direction in directions:
            new_x, new_y = x + dx, y + dy
            if 0 <= new_x < m and 0 <= new_y < n and (new_x, new_y) not in visited and grid[new_y][new_x] != '#':
                visited.add((new_x, new_y))
                queue.append((new_x, new_y, path + direction))
    print("NO")
    return

if __name__ == "__main__":
    abandoned_warehouse()

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: TIME LIMIT EXCEEDED

Test 10

Verdict: TIME LIMIT EXCEEDED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: TIME LIMIT EXCEEDED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: TIME LIMIT EXCEEDED