#!/usr/bin/env python
# coding: utf-8

# In[5]:


H,W,A,B = map(int, input().split())


# In[6]:


for i in range(H):
    if i < B:
        tmp = "0"*A + "1"*(W-A)
    else:
        tmp = "1"*A + "0"*(W-A)
    print(tmp)


# In[ ]:



 H,W,A,B = map(int, input().split()) H map(int, input().split()) map int input().split() ().split () input split W A B for i in range(H):
    if i < B:
        tmp = "0"*A + "1"*(W-A)
    else:
        tmp = "1"*A + "0"*(W-A)
    print(tmp)


# In[ ]: i range(H) range H if i < B:
        tmp = "0"*A + "1"*(W-A)
    else:
        tmp = "1"*A + "0"*(W-A)
     i < B i B tmp = "0"*A + "1"*(W-A) tmp "0"*A + "1"*(W-A) "0"*A "0" A "1"*(W-A) "1" W-A W A tmp = "1"*A + "0"*(W-A) tmp "1"*A + "0"*(W-A) "1"*A "1" A "0"*(W-A) "0" W-A W A print(tmp) print tmp B = map(int, input().split()) map(int, input().split()) B tmp = "1"*A + "0"*(W-A) "1"*A + "0"*(W-A) tmp H,W,A,B = map(int, input().split()) map(int, input().split()) H A,B = map(int, input().split()) map(int, input().split()) A tmp = "0"*A + "1"*(W-A) "0"*A + "1"*(W-A) tmp W,A,B = map(int, input().split()) map(int, input().split()) W
#!/usr/bin/env python
# coding: utf-8

# In[5]:


H,W,A,B = map(int, input().split())


# In[6]:


for i in range(H):
    if i < B:
        tmp = "0"*A + "1"*(W-A)
    else:
        tmp = "1"*A + "0"*(W-A)
    print(tmp)


# In[ ]:




