#include<stdio.h>
#include<string.h>
char*mapping[] = {"","","ABC";"DEF","GHI","JKL","MNO","PQRS","TUV","WXYZ"};
void generate(char digits[],char output[],int index,int len)
{
    if(index == len)
    {
        printf("%s",output);
        return;
    }
    int digit = digits[index]-'0';
    char*letters = mapping[digit];
    for(int i=0;i<strlen(letters);i++)
    {
        output[index] = letters[i];
        generate(digits,output,index + 1,len);
    }
}
int main()
{
    char digits[20];
    scanf("%s",digits);
    int len = strlen(digits);
    for(int i=0;i<len;i++)
    {
        if(digits[i]<'2'||digits[i]>'9')
        {
            printf("Invalid input");
            return 0;
        }
    }
    char output[20];
    output[len]='\0';
    generate(digits,output,0,len);
    return 0;
}