Positive integer n is given. Find how many different numbers among the numbers nmod1, nmod2, …, nmodn.
One integer n (1≤n≤1012).
Print one number — the number of different integers among nmod1, nmod2, …, nmodn.
In the first example we consider only one number: 1 bmod1=0, so the answer is 1.
In the second example we have 2mod1=2mod2=0, so the answer is 1.
In the third example we have 3mod1=3mod3=0, and also 3mod2=1, just two different numbers.