#include <iostream>
#include <fstream>
using namespace std;

int main()
{
ifstream file;
int i =0;
int n=1;
char print[50];
char c;
int j=0;/*number of space and special chars. if divisible by 3 then print*/

/*open file*/
file.open("example.txt");
if ( file.fail() )
{
	cout<< "There is no file named \"example\""<<endl;
	return(0);
}

while (file.good())
{
	c = file.get();
	if ( (c<=(int)'9' && c>=(int)'0')||(c<=(int)'Z' && c>=(int)'A')||(c<=(int)'z' && c>=(int)'a') )
	{
		if(j%3==0)
		{
		print[i]=c;
		cout << print[i];
		i++;
		n=2;
		} else n=3;
	}else
	{
		switch(n)
		{
		case 3:
			j++;n=1;break;
		case 2:
			print[i]=' ';
			cout << print[i];
			i++;
			n=1;j++;break;
		}
	}
}
}