import sys
input = sys.stdin.readline
from heapq import heappush,heappop,heapify,heappushpop,heapreplace,merge,nlargest,nsmallest


H,W,Y,X=map(int,input().split())
A=[list(map(int,input().split())) for _ in range(H)]
INF=float("inf")
pow = 0

que = [(A[Y-1][X-1],Y-1,X-1)]
while que:
    a,y,x=heappop(que)
    if A[y][x]==0:continue
    # if A[y][x]>=pow:break
    pow+=A[y][x]
    A[y][x]=0
    for ny,nx in [(y-1,x),(y+1,x),(y,x-1),(y,x+1)]:
        if 0<=ny<H and 0<=nx<W:
            if A[ny][nx]>0:
                heappush(que,(A[ny][nx],ny,nx))

for y in range(H):
    if any([a!=0 for a in A[y]]):
        print("No")
        break
else:
    print("Yes")