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(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(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(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" A "1" * (W - A) "1" W - A W A row = "1" * A + "0" * (W - A) row "1" * A + "0" * (W - A) "1" * A "1" A "0" * (W - A) "0" W - A W A print(row) print 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(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(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(row)


if __name__ == "__main__":
    main()