no idea for a simple c code

I am doing a simple c coding for print all the possible combination of characters "y,t,a,r,m,h,e" without repeat any character.

I have been print for "1,2,3,4,5" but have not any idea for characters "y,t,a,r,m,h,e".

i can only use while, for, if, break, continue, case because have not learn yet about array, function, pointer.....

i was thinking about 7 loops each about times but

#include<stdio.h>
#include<conio.h>
main()
{
      int i,j,k,l,m,n,o,p;
      char a;
      for(i=1;i<=7;i++)
      {
      for(j=1;j<=7;j++)
      {
      for(k=1;k<=7;k++)
      {
      for(l=1;l<=7;l++)
      {
      for(m=1;m<=7;m++)
      {
      for(n=1;n<=7;n++)
      {
      for(o=1;o<=7;o++)
      {
      for(p=1;p<=7;p++)
      {
      /*what should be here, am i going right*/
      }
      }
      }
      }
      }
      }
      }                 
      }
      }