Crazy notions
Time Limit: 1.0 second
Memory Limit: 1 000 КБ

For five days robot-loader JK546L54p has been buried under the thick layer of the Sibelian plutonium slag. The terrible strike of the atmospheric electricity has led to the depressurization of the robot’s fuel elements. Who will examine this heap of fused, broken metal here, where there is no any robot technician even at distance of a hundred parsecs? Robot-commissar even did not try to investigate what happened with JK546L54p. He ordered to throw him out into dumps and that is all. Nobody noticed that positron brains of JK546L54p were still working. If only the robopsychologist was here with JK546L54p! Of course, he would be killed with the hard gamma radiation in a moment, but… If he attached the visualizer of thoughts to the fused connectors of JK546L54p! He would see the strange performance. Robot was creating! No, I am not joking. He was investigating. Semi casual objects arose in his mind, and he examined them. Crazy properties, crazy theorems.

Besides, here is an example. Let’s take an expression 1n+2n+3n+4n. With how mach zeros ends its decimal notation? JK546L54p solved this problem, and you, student, could you?

Input
In the input there is only one positive integer number n (n <= 300000).

Output
Ð?а выходе должно Ñ?одержатьÑ?Ñ? единÑ?твенное чиÑ?ло – чиÑ?ло нулей, на которые оканчиваетÑ?Ñ? деÑ?Ñ?тичнаÑ? запиÑ?ÑŒ.

Sample Input
Sample input #1
1

Sample input #2
3
Sample Output
Sample output #1
1

Sample output #2
2