Suppose that  $\{a_n\}$ is an arithmetic sequence with $$
a_1+a_2+ \cdots +a_{100}=100 \quad \text{and} \quad
a_{101}+a_{102}+ \cdots + a_{200}=200.
$$What is the value of $a_2 - a_1$? Express your answer as a common fraction.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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