import sys
def input():
    return sys.stdin.readline()[:-1]

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

ANS = [None]*H
for i in range(H):
    ANS[i] = ['0']*W
for i in range(H):
    for j in range(W):
        if j<A and i>=B:
            ANS[i][j] = '1'
        elif j>=A and i<B:
            ANS[i][j] = '1'
for i in range(H):
    print(''.join(ANS[i]))