An integer $x$, with $10 \leq x \leq 99$, is to be chosen.  If all choices are equally likely, what is the probability that at least one digit of $x$ is a 7?The answer is in the form rac{m}{n}, where gcd(m, n) = 1. Please provide the value of m + n.

Let's think step by step and output the final answer within \boxed{}.
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