Question 1111875
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Calculate the highest degree of 5 in the product: it will give you the number of zeroes.


The highest degree of 5 is equal to


[n/5] + [n/5^2] + [n/5^3] + . . . + [n/5^m],


where [x] means the "integer part" of the number x  (do not ask me what is it - you must know it); 
 
the index "m" is the highest degree the number  {{{5^m}}}  still divides n.
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