import sys


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            print("".join(["0"] * a + ["1"] * (w - a)))
        else:
            print("".join(["1"] * a + ["0"] * (w - a)))


if __name__ == '__main__':
    solve() import sys sys def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            print("".join(["0"] * a + ["1"] * (w - a)))
        else:
            print("".join(["1"] * a + ["0"] * (w - a))) solve input = sys.stdin.readline input sys.stdin.readline sys.stdin sys stdin readline mod = 10 ** 9 + 7 mod 10 ** 9 + 7 10 ** 9 10 9 7 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:
            print("".join(["0"] * a + ["1"] * (w - a)))
        else:
            print("".join(["1"] * a + ["0"] * (w - a))) i range(h) range h if i < b:
            print("".join(["0"] * a + ["1"] * (w - a)))
        else:
            print("".join(["1"] * a + ["0"] * (w - a))) i < b i b print("".join(["0"] * a + ["1"] * (w - a))) print "".join(["0"] * a + ["1"] * (w - a)) "".join "" join ["0"] * a + ["1"] * (w - a) ["0"] * a ["0"] "0" a ["1"] * (w - a) ["1"] "1" w - a w a print("".join(["1"] * a + ["0"] * (w - a))) print "".join(["1"] * a + ["0"] * (w - a)) "".join "" join ["1"] * a + ["0"] * (w - a) ["1"] * a ["1"] "1" a ["0"] * (w - a) ["0"] "0" w - a w a if __name__ == '__main__':
    solve() __name__ == '__main__' __name__ '__main__' solve() solve def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            print("".join(["0"] * a + ["1"] * (w - a)))
        else:
            print("".join(["1"] * a + ["0"] * (w - a))) def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            print("".join(["0"] * a + ["1"] * (w - a)))
        else:
            print("".join(["1"] * a + ["0"] * (w - a))) solve
import sys


def solve():
    input = sys.stdin.readline
    mod = 10 ** 9 + 7
    h, w, a, b = list(map(int, input().rstrip('\n').split()))
    for i in range(h):
        if i < b:
            print("".join(["0"] * a + ["1"] * (w - a)))
        else:
            print("".join(["1"] * a + ["0"] * (w - a)))


if __name__ == '__main__':
    solve()
