def main():
    H, W, A, B = map(int, input().split())
    l1 = [0]*A + [1]*(W-A)
    l2 = [1]*A + [0]*(W-A)
    s1 = ''.join(map(str, l1))
    s2 = ''.join(map(str, l2))
    for i in range(B):
        print(s1)
    for i in range(B, H):
        print(s2)

if __name__ == '__main__':
    main() def main():
    H, W, A, B = map(int, input().split())
    l1 = [0]*A + [1]*(W-A)
    l2 = [1]*A + [0]*(W-A)
    s1 = ''.join(map(str, l1))
    s2 = ''.join(map(str, l2))
    for i in range(B):
        print(s1)
    for i in range(B, H):
        print(s2) main H, W, A, B = map(int, input().split()) H map(int, input().split()) map int input().split() ().split () input split W A B l1 = [0]*A + [1]*(W-A) l1 [0]*A + [1]*(W-A) [0]*A [0] 0 A [1]*(W-A) [1] 1 W-A W A l2 = [1]*A + [0]*(W-A) l2 [1]*A + [0]*(W-A) [1]*A [1] 1 A [0]*(W-A) [0] 0 W-A W A s1 = ''.join(map(str, l1)) s1 ''.join(map(str, l1)) ''.join '' join map(str, l1) map str l1 s2 = ''.join(map(str, l2)) s2 ''.join(map(str, l2)) ''.join '' join map(str, l2) map str l2 for i in range(B):
        print(s1)
     i range(B) range B print(s1) print s1 for i in range(B, H):
        print(s2) i range(B, H) range B H print(s2) print s2 if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def main():
    H, W, A, B = map(int, input().split())
    l1 = [0]*A + [1]*(W-A)
    l2 = [1]*A + [0]*(W-A)
    s1 = ''.join(map(str, l1))
    s2 = ''.join(map(str, l2))
    for i in range(B):
        print(s1)
    for i in range(B, H):
        print(s2) def main():
    H, W, A, B = map(int, input().split())
    l1 = [0]*A + [1]*(W-A)
    l2 = [1]*A + [0]*(W-A)
    s1 = ''.join(map(str, l1))
    s2 = ''.join(map(str, l2))
    for i in range(B):
        print(s1)
    for i in range(B, H):
        print(s2) main
def main():
    H, W, A, B = map(int, input().split())
    l1 = [0]*A + [1]*(W-A)
    l2 = [1]*A + [0]*(W-A)
    s1 = ''.join(map(str, l1))
    s2 = ''.join(map(str, l2))
    for i in range(B):
        print(s1)
    for i in range(B, H):
        print(s2)

if __name__ == '__main__':
    main()
