import sys

input = sys.stdin.readline


def main():
    H, W, A, B = map(int, input().split())

    line = [0] * A + [1] * (W - A)
    X = "".join(map(str, line))
    ans = [""] * H
    for i in range(H):
        if i == B:
            X = "".join(map(lambda x: str(x ^ 1), line))
        ans[i] = X

    print(*ans, sep="\n")


if __name__ == "__main__":
    main() import sys sys input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline def main():
    H, W, A, B = map(int, input().split())

    line = [0] * A + [1] * (W - A)
    X = "".join(map(str, line))
    ans = [""] * H
    for i in range(H):
        if i == B:
            X = "".join(map(lambda x: str(x ^ 1), line))
        ans[i] = X

    print(*ans, sep="\n") main H, W, A, B = map(int, input().split()) H map(int, input().split()) map int input().split() ().split () input split W A B line = [0] * A + [1] * (W - A) line [0] * A + [1] * (W - A) [0] * A [0] 0 A [1] * (W - A) [1] 1 W - A W A X = "".join(map(str, line)) X "".join(map(str, line)) "".join "" join map(str, line) map str line ans = [""] * H ans [""] * H [""] "" H for i in range(H):
        if i == B:
            X = "".join(map(lambda x: str(x ^ 1), line))
        ans[i] = X

     i range(H) range H if i == B:
            X = "".join(map(lambda x: str(x ^ 1), line))
         i == B i B X = "".join(map(lambda x: str(x ^ 1), line)) X "".join(map(lambda x: str(x ^ 1), line)) "".join "" join map(lambda x: str(x ^ 1), line) map lambda x: str(x ^ 1) str(x ^ 1) str x ^ 1 x 1 x line ans[i] = X ans[i] ans i X print(*ans, sep="\n") print *ans ans sep="\n" sep "\n" if __name__ == "__main__":
    main() __name__ == "__main__" __name__ "__main__" main() main def main():
    H, W, A, B = map(int, input().split())

    line = [0] * A + [1] * (W - A)
    X = "".join(map(str, line))
    ans = [""] * H
    for i in range(H):
        if i == B:
            X = "".join(map(lambda x: str(x ^ 1), line))
        ans[i] = X

    print(*ans, sep="\n") def main():
    H, W, A, B = map(int, input().split())

    line = [0] * A + [1] * (W - A)
    X = "".join(map(str, line))
    ans = [""] * H
    for i in range(H):
        if i == B:
            X = "".join(map(lambda x: str(x ^ 1), line))
        ans[i] = X

    print(*ans, sep="\n") main input = sys.stdin.readline sys.stdin.readline input
import sys

input = sys.stdin.readline


def main():
    H, W, A, B = map(int, input().split())

    line = [0] * A + [1] * (W - A)
    X = "".join(map(str, line))
    ans = [""] * H
    for i in range(H):
        if i == B:
            X = "".join(map(lambda x: str(x ^ 1), line))
        ans[i] = X

    print(*ans, sep="\n")


if __name__ == "__main__":
    main()
