Darnell has 1000 square feet of fabric that he's using to make mini flags. He makes square flags that are 4 feet by 4 feet, wide rectangular flags that are 5 feet by 3 feet, and tall rectangular flags that are 3 feet by 5 feet. He has already made 16 square flags, 20 wide flags, and 10 tall flags. How many square feet of fabric does he have left?
Please reason step by step, and put your final answer within \boxed{}.
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