def slove():
    import sys
    input = sys.stdin.readline
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            t = ["0"] * a
            s = ["1"] * (w - a)
            print("".join(t + s))
        else:
            t = ["1"] * a
            s = ["0"] * (w - a)
            print("".join(t + s))


if __name__ == '__main__':
    slove() def slove():
    import sys
    input = sys.stdin.readline
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            t = ["0"] * a
            s = ["1"] * (w - a)
            print("".join(t + s))
        else:
            t = ["1"] * a
            s = ["0"] * (w - a)
            print("".join(t + s)) slove import sys sys input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline h, w, a, b = list(map(int, input().rstrip('\n').split())) h list(map(int, input().rstrip('\n').split())) list map(int, input().rstrip('\n').split()) map int input().rstrip('\n').split() ().rstrip('\n').split ().rstrip('\n') ().rstrip () input rstrip '\n' split w a b for i in range(h):
        if i < b:
            t = ["0"] * a
            s = ["1"] * (w - a)
            print("".join(t + s))
        else:
            t = ["1"] * a
            s = ["0"] * (w - a)
            print("".join(t + s)) i range(h) range h if i < b:
            t = ["0"] * a
            s = ["1"] * (w - a)
            print("".join(t + s))
        else:
            t = ["1"] * a
            s = ["0"] * (w - a)
            print("".join(t + s)) i < b i b t = ["0"] * a t ["0"] * a ["0"] "0" a s = ["1"] * (w - a) s ["1"] * (w - a) ["1"] "1" w - a w a print("".join(t + s)) print "".join(t + s) "".join "" join t + s t s t = ["1"] * a t ["1"] * a ["1"] "1" a s = ["0"] * (w - a) s ["0"] * (w - a) ["0"] "0" w - a w a print("".join(t + s)) print "".join(t + s) "".join "" join t + s t s if __name__ == '__main__':
    slove() __name__ == '__main__' __name__ '__main__' slove() slove def slove():
    import sys
    input = sys.stdin.readline
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            t = ["0"] * a
            s = ["1"] * (w - a)
            print("".join(t + s))
        else:
            t = ["1"] * a
            s = ["0"] * (w - a)
            print("".join(t + s)) def slove():
    import sys
    input = sys.stdin.readline
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            t = ["0"] * a
            s = ["1"] * (w - a)
            print("".join(t + s))
        else:
            t = ["1"] * a
            s = ["0"] * (w - a)
            print("".join(t + s)) slove
def slove():
    import sys
    input = sys.stdin.readline
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            t = ["0"] * a
            s = ["1"] * (w - a)
            print("".join(t + s))
        else:
            t = ["1"] * a
            s = ["0"] * (w - a)
            print("".join(t + s))


if __name__ == '__main__':
    slove()
