#include <stdio.h>
int main ()
{
    char mystrings[8][5] = { {"ABC"},{"DEF"},{"GHI"},{"JKL"},{"MNO"},
                             {"PQRS"},{"TUV"},{"WXYZ"} };
    int i=0,j=0,k=0;
    int num;
    int leftdigit, middigit, rightdigit;
    int counter=0;

    printf("Enter a number (3-digit): ");
    scanf("%d", &num);
    printf("\n");

    if (num%10 == 0 || num%10 == 1)
       printf("Invalid input! The number should not contain 0 or 1.\n\n");
    else if (((num/10)%10 == 0) || ((num/10)%10 == 1))
       printf("Invalid input! The number should not contain 0 or 1.\n\n");
    else if (((num/100)%10 == 0) || ((num/100)%10 == 1))
       printf("Invalid input! The number should not contain 0 or 1.\n\n");
    else
      {
        printf("The combinations are:\n");
        leftdigit=num/100-2;
        middigit=(num/10)%10-2;
        rightdigit=num%10-2;

        for(i=0;i<=4;i++)
         for(j=0;j<=4;j++)
           for(k=0;k<=4;k++)
            {
             if(mystrings[leftdigit][i]!=NULL && mystrings[middigit][j]!=NULL && mystrings[rightdigit][k]!=NULL)
              {
               printf("%c%c%c, ", mystrings[leftdigit][i], mystrings[middigit][j], mystrings[rightdigit][k]);
               counter++;
              }
             if(counter%8==0)
               printf("\n");
            }
      }
    system("PAUSE");
    return 0;
}