How many feet of paper does it take to write "Heaven rewards diligence" in Chinese calligraphy?

Four feet is a little big, just write four words, and three feet (two) is better for eight words. The size of the three-foot poster is about 100*50cm. I have some experience in this field. I have written these four words to my class many times from elementary school to junior high school. I think there should be a gap between two pieces of paper, not next to each other. If you want to hang them on the side, you can announce them with four feet.