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A prime is the number which can be only divide exactly by $1$ or itself.
There several test case. Each test case have two positive integer $N,M$ in one line. $(0<N \leqslant M<10^6)$
For each test case, output one line that contain an integer that is the number of primes from $N$ to $M$.
5 10 1 3 6 8
2 2 1