A fraction is equivalent to $\frac{5}{8}.$ Its denominator and numerator add up to $91.$ What is the difference between the denominator and numerator of this fraction?
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
A fraction is equivalent to $\frac{5}{8}.$ Its denominator and numerator add up to $91.$ What is the difference between the denominator and numerator of this fraction?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
21
A fraction is equivalent to $\frac{5}{8}.$ Its denominator and numerator add up to $91.$ What is the difference between the denominator and numerator of this fraction?
train