#include <stdio.h>
int main( int argv, char *argc[] )
{
   int character;
   int previous;

   while ((character = getchar()) != EOF) {
       switch (character) {
       case ' ':  if (previous != ' ') putchar(character); break;
       case '\t': putchar('\\'); putchar('t'); break;
       case '\b': putchar('\\'); putchar('b'); break;
       case '\\': putchar('\\'); putchar('\\'); break;
       default:   putchar(character);
       }

       previous = character;
   }
   return 0;
}