/*
  While loops are always used for reading file. see Nyhoff P132-133
*/

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

/*
   while (file or stream has input)
     {
        read input
        process input
     }

   No input is read if the file does not contain any.
*/

int main()
{
   string s;
   while (cin >> s)                         // returns false when cin can't read string
     {                                      // use ctrl+d  or ctrl+c to send end-of-file to exit loop.
        cout << ":\t" << s << endl;         // print it out \t denotes tab space
     }

   return 0;
}