#!/usr/bin python3
# -*- coding: utf-8 -*-

def main():
    h, w, a, b = map(int, input().split())
    for i in range(b):
        print('1'*a + '0'*(w-a))
    for i in range(h-b):
        print('0'*a + '1'*(w-a))

if __name__ == '__main__':
    main() def main():
    h, w, a, b = map(int, input().split())
    for i in range(b):
        print('1'*a + '0'*(w-a))
    for i in range(h-b):
        print('0'*a + '1'*(w-a)) 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(b):
        print('1'*a + '0'*(w-a))
     i range(b) range b print('1'*a + '0'*(w-a)) print '1'*a + '0'*(w-a) '1'*a '1' a '0'*(w-a) '0' w-a w a for i in range(h-b):
        print('0'*a + '1'*(w-a)) i range(h-b) range h-b h b print('0'*a + '1'*(w-a)) print '0'*a + '1'*(w-a) '0'*a '0' a '1'*(w-a) '1' w-a w a if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def main():
    h, w, a, b = map(int, input().split())
    for i in range(b):
        print('1'*a + '0'*(w-a))
    for i in range(h-b):
        print('0'*a + '1'*(w-a)) def main():
    h, w, a, b = map(int, input().split())
    for i in range(b):
        print('1'*a + '0'*(w-a))
    for i in range(h-b):
        print('0'*a + '1'*(w-a)) main
#!/usr/bin python3
# -*- coding: utf-8 -*-

def main():
    h, w, a, b = map(int, input().split())
    for i in range(b):
        print('1'*a + '0'*(w-a))
    for i in range(h-b):
        print('0'*a + '1'*(w-a))

if __name__ == '__main__':
    main()