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


if __name__ == "__main__":
    main() def main():
    H, W, A, B = map(int, input().split())
    
    for i in range(H):
        if i < B:
            row = ["0"] * A + ["1"] * (W - A)
        else:
            row = ["1"] * A + ["0"] * (W - A)
        print("".join(row)) main 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:
            row = ["0"] * A + ["1"] * (W - A)
        else:
            row = ["1"] * A + ["0"] * (W - A)
        print("".join(row)) i range(H) range H if i < B:
            row = ["0"] * A + ["1"] * (W - A)
        else:
            row = ["1"] * A + ["0"] * (W - A)
         i < B i B row = ["0"] * A + ["1"] * (W - A) row ["0"] * A + ["1"] * (W - A) ["0"] * A ["0"] "0" A ["1"] * (W - A) ["1"] "1" W - A W A row = ["1"] * A + ["0"] * (W - A) row ["1"] * A + ["0"] * (W - A) ["1"] * A ["1"] "1" A ["0"] * (W - A) ["0"] "0" W - A W A print("".join(row)) print "".join(row) "".join "" join row if __name__ == "__main__":
    main() __name__ == "__main__" __name__ "__main__" main() main def main():
    H, W, A, B = map(int, input().split())
    
    for i in range(H):
        if i < B:
            row = ["0"] * A + ["1"] * (W - A)
        else:
            row = ["1"] * A + ["0"] * (W - A)
        print("".join(row)) def main():
    H, W, A, B = map(int, input().split())
    
    for i in range(H):
        if i < B:
            row = ["0"] * A + ["1"] * (W - A)
        else:
            row = ["1"] * A + ["0"] * (W - A)
        print("".join(row)) main
def main():
    H, W, A, B = map(int, input().split())
    
    for i in range(H):
        if i < B:
            row = ["0"] * A + ["1"] * (W - A)
        else:
            row = ["1"] * A + ["0"] * (W - A)
        print("".join(row))


if __name__ == "__main__":
    main()