import heapq as hq
H, W, Y, X = map(int, input().split())
A = [list(map(int, input().split())) for _ in range(H)]
Y -= 1
X -= 1
seen = [[0]*W for _ in range(H)]
seen[Y][X] = 1
v = A[Y][X]
A[Y][X] = 0
ct = 0

mv = [[1, 0], [0, 1], [-1, 0], [0, -1]]
task = [(0, Y, X)]
while task:
    d, x, y = hq.heappop(task)
    if d >= v:
        break
    v += d
    ct += 1
    for mx, my in mv:
        nx, ny = x+mx, y+my
        if not (0 <= nx < H and 0 <= ny < W):
            continue
        if seen[nx][ny]:
            continue
        hq.heappush(task, (A[nx][ny], nx, ny))
        seen[nx][ny] = 1

print('Yes' if ct == H*W else 'No')