def main():
  h,w,a,b=map(int,input().split())
  
  ans=[]
  ans+=["0"*a + "1"*(w-a) + "\n"]*b
  ans+=["1"*a + "0"*(w-a) + "\n"]*(h-b)
  print("".join(ans)[:-1])
  
if __name__=="__main__":
  main() def main():
  h,w,a,b=map(int,input().split())
  
  ans=[]
  ans+=["0"*a + "1"*(w-a) + "\n"]*b
  ans+=["1"*a + "0"*(w-a) + "\n"]*(h-b)
  print("".join(ans)[:-1])
   main h,w,a,b=map(int,input().split()) h map(int,input().split()) map int input().split() ().split () input split w a b ans=[] ans [] ans+=["0"*a + "1"*(w-a) + "\n"]*b ans ["0"*a + "1"*(w-a) + "\n"]*b ["0"*a + "1"*(w-a) + "\n"] "0"*a + "1"*(w-a) + "\n" "0"*a + "1"*(w-a) "0"*a "0" a "1"*(w-a) "1" w-a w a "\n" b ans+=["1"*a + "0"*(w-a) + "\n"]*(h-b) ans ["1"*a + "0"*(w-a) + "\n"]*(h-b) ["1"*a + "0"*(w-a) + "\n"] "1"*a + "0"*(w-a) + "\n" "1"*a + "0"*(w-a) "1"*a "1" a "0"*(w-a) "0" w-a w a "\n" h-b h b print("".join(ans)[:-1]) print "".join(ans)[:-1] "".join(ans) "".join "" join ans :-1 -1 if __name__=="__main__":
  main() __name__=="__main__" __name__ "__main__" main() main def main():
  h,w,a,b=map(int,input().split())
  
  ans=[]
  ans+=["0"*a + "1"*(w-a) + "\n"]*b
  ans+=["1"*a + "0"*(w-a) + "\n"]*(h-b)
  print("".join(ans)[:-1])
   def main():
  h,w,a,b=map(int,input().split())
  
  ans=[]
  ans+=["0"*a + "1"*(w-a) + "\n"]*b
  ans+=["1"*a + "0"*(w-a) + "\n"]*(h-b)
  print("".join(ans)[:-1])
   main
def main():
  h,w,a,b=map(int,input().split())
  
  ans=[]
  ans+=["0"*a + "1"*(w-a) + "\n"]*b
  ans+=["1"*a + "0"*(w-a) + "\n"]*(h-b)
  print("".join(ans)[:-1])
  
if __name__=="__main__":
  main()